Construction of Dispiro-Indenone Scaffolds via Domino Cycloaddition Reactions of α,β-Unsaturated Aldimines with 2-Arylidene-1,3-indenediones and 2,2'-(Arylmethylene)bis(1,3-indenediones).

The catalyst-free domino reaction of α,β-unsaturated N-alkyl or N-arylaldimines with two molecules of 2-arylidene-1,3-indanediones in dry acetonitrile resulted in polysubstituted spiro[indene-2,3'-indeno[2',1':5,6]pyrano[2,3-b]pyridines] in moderate to good yields and with high diastereoselectivity. The reaction mechanism included sequential aza/oxa-Diels-Alder reactions via both endo-transition states. On the other hand, the catalyst-free domino reaction of α,β-unsaturated N-arylaldimines with 2,2'-(arylmethylene)bis(1,3-indenediones) afforded the mixed diastereoisomeric dispiro[indene-2,1'-cyclohexane-3',2″-indene] derivatives in satisfactory yields. The reaction mechanism of this formal [3 + 3] cycloaddition was believed to proceed with sequential nucleophilic 1,4-/1,2-additions.

Introduction

Indanone-containing heterocycles are one of the important heterocyclic scaffolds present in various alkaloids and possessing a broad array of biological functions.[1,2] For example, coleophomone D existed in a state of flux between different isomeric forms and possessed antifungal action and the ability to inhibit the serine protease enzyme and heart chymase.[3] 4-Azafluorenone and its derivatives exhibit cytotoxic, phosphodiesterase inhibitory, coronary dilating, and calcium modulating activities as well as antimicrobial and antituberculosis agents.[4] Typically, indenopyridone NSC 314622 serving as a lead compound for the evolution of anticance agents targeting topoisomerase I.[5] A series of spirocyclic ketones with bi/terphenyls are potential leads for development as new anticancer agents and chemical probes to study signaling networks in neoplastic cells.[6] Tricyclic 2,3-dicyano indanopyrazinone acts as an efficient nonquinone oxidoreductase (NQO1) substrate and may be a new option for the treatment of NQO1-overexpresssing drug-resistant lung cancer (Figure ).[7] On the other hand, some indanone-containing polymers were widely employed in the various materials such as nonlinear optical, organic photovoltaics, and semiconductors.[8]

Figure 1

Some indanone-containing heterocycles with biological property.

Because of the important biological activities they exhibit, significant synthetic effects have been devoted to the synthesis of indanone-containing heterocycles.[9,10] For constructing diverse indanone-containing polycyclic systems, the readily available 1,3-indanedione was regarded as an active substrate because it has three contiguous electrophilic and nucleophilic reactive sites.[11−13] On the other hand, easily prepared 2-arylidene-1,3-indanediones are typical 1,3-dipolarophiles and dienophiles. 2-Arylidene-1,3-indanediones have been widely employed in many Michael addition, condensation reaction, Diels–Alder reaction, cyclization reaction, as well as domino multicomponent reactions.[14−18] Recently, we have found that a domino aza-/oxa-Diels–Alder reaction of α,β-unsaturated N-arylaldimines with 5-arylidene-1,3-dimethylbarbituric acids resulted in polycyclic spiro[pyrido[3′,2′:5,6]pyrano[2,3-d]pyrimidine-7,5′-pyrimidine] derivatives.[19] This unique reaction provided an elegant synthetic protocol for the construction of the polycyclic spiro compounds from the combination of aza-/oxa-Diels–Alder reactions in a one-pot reaction procedure. In order to further demonstrate the potential synthetic values of this reaction for the spiro compounds, we initialed the systematic investigation of various 1-aza-1,4-butadienes and versatile dienophiles in the domino reactions. Herein, we wish to report the domino reaction of α,β-unsaturated aldimines and 2-arylidene-1,3-indanediones for the efficient synthesis of polysubstituted spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridines]. In this domino reaction, 5-arylidene-1,3-indanedione not only acted as an active dienophile, but also played as a useful 1-oxa-1,4-diene to finish the sequential aza-/oxa-Diels–Alder reaction.

Results and Discussion

At first, according to our previously established reaction conditions for the reaction of α,β-unsaturated N-arylaldimines with 2-arylidene-N,N′-dimethylbarbituric acids,[19] a mixture of 2-(p-bromobenzylidene)-1.3-indanedione 1a and N-(4-methoxyphenyl)-3-(p-tolyl)prop-2-en-1-imine 2a was stirred in methylene dichloride at room temperature overnight, the expected polycyclic spiro compound 3a was successfully obtained in 31% (Table ). When the reaction was carried out in refluxing methylene dichloride for eight or 12 h, the yields of 3a increased to 42 and 45%, respectively. The reaction in ethanol did not give the expected product. On the other hand, the reaction in tetrahydrofuran and toluene also resulted in product 3a in lower yields. When acetonitrile was employed as the solvent, the reaction afforded product 3a in 20% yield at room temperature. At the elevated temperature (60 °C), 3a was obtained in 68% yield. When a slight excess of α,β-unsaturated aldimine was used, the yield of 3a increased to 78% yield. The reaction in refluxing acetonitrile decreased the yield of 3a to 73%. Finally, the reaction in a nitrogen atmosphere afforded 3a in a high yield (82%).

Table 1

Optimizing Reaction Conditionsa

entry	solvent	ratio	T (°C)	time (h)	yield (%)b
1	DCM	2:1	rt	6	31
2	DCM	2:1	reflux	8	42
3	DCM	2:1	reflux	12	45
4	EtOH	2:1	rt	8
5	EtOH	2:1	reflux	8
6	toluene	2:1	rt	6	10
7	toluene	2:1	reflux	12	21
8	THF	2:1	rt	8	26
9	THF	2:1	reflux	12	26
10	MeCN	2:1	rt	12	20
11	MeCN	2:1	60	6	68
12	MeCN	2:1.1	60	6	78
13	MeCN	2:1.1	reflux	10	73
14	MeCN	2:1.1	60	6	82c

Reaction conditions: α,β-unsaturated N-arylaldimine, 2-arylidene-1,3-indanedione, solvent (10.0 mL).

Isolated yields.

N2, in Schenk tube.

With the optimized reaction conditions in hand, the scope of the reactions was thoroughly investigated. The results are summarized in Table . At first, 2-arylidene-1,3-indanediones with electron-withdrawing fluoro, chloro, bromo, and nitro groups resulted in the spiropolycycles 3a–3p in 65–86% yields. In these reactions, α,β-unsaturated aldimines with electron-donating substituents such as methoxy, methyl, and electron-withdrawing substituents such as chloro, bromo, and nitro groups can be successfully employed in the reaction and showed less effect to the yields of products. Second, 2-benzylidene-1,3-indanediones gave the desired spiropolycycles 3q–3s in moderate yields. Third, 2-(4-methylbenzylidene)-1,3-indanediones afforded the products 3t–3v in lower yields. However, 2-arylidene-1,3-indanediones with m-methyl, m-methoxy, and p-methoxy groups did not result in the expected spiropolycycles. In these reactions, the retro-Knoevenagel condensation reaction of α,β-unsaturated aldimines with 2-arylidene-1,3-indanediones quickly resulted in 2-styrylidene-1,3-indanediones, which can be clearly determined by thin-layer chromatography (TLC) monitoring and were isolated in moderate yields. This cross exchange phenomenon was recently described by Lehn and co-workers as a dynamic covalent metathesis in the C=C/C=N exchange between Knoevenagel compounds and imines involving the formation of a four-membered azetidine ring intermediate.[20] The structures of the above-obtained spiropolycycles 3a–3v were fully characterized with infrared (IR), high-resolution mass spectra (HRMS), and 1H and 13C NMR spectroscopy. Through several diastereoisomers might be formed in the reaction, TLC monitoring and 1H and 13C NMR spectra clearly showed that there is only one set of characteristic absorptions for the protons in the molecule, which also indicated only one diastereoisomer existed in the obtained products.

Table 2

Synthesis of Spiropolycycles 3a–3v via the Aza/Oxa-Diels–Alder Reactiona

entry	compd	Ar1	Ar2	Ar3	yield (%)b
1	3a	p-BrC6H4	p-CH3C6H4	p-CH3OC6H4	82
2	3b	p-BrC6H4	p-CH3OC6H4	p-CH3OC6H4	86
3	3c	p-BrC6H4	p-FC6H4	p-CH3OC6H4	71
4	3d	p-BrC6H4	p-NO2C6H4	p-CH3OC6H4	65
5	3e	p-BrC6H4	Ph	Ph	79
6	3f	p-BrC6H4	Ph	p-CH3OC6H4	86
7	3g	p-BrC6H4	Ph	p-BrC6H4	82
8	3h	p-NO2C6H4	Ph	Ph	75
9	3i	p-NO2C6H4	Ph	p-CH3OC6H4	80
10	3j	p-NO2C6H4	Ph	p-BrC6H4	71
11	3k	o-ClC6H4	Ph	p-CH3OC6H4	76
12	3l	o-BrC6H4	Ph	p-CH3C6H4	85
13	3m	m-ClC6H4	Ph	Ph	73
14	3n	m-ClC6H4	Ph	p-CH3OC6H4	69
15	3o	m-ClC6H4	Ph	p-BrC6H4	78
16	3p	m-FC6H4	Ph	Ph	68
17	3q	Ph	Ph	Ph	53
18	3r	Ph	Ph	p-CH3OC6H4	48
19	3s	Ph	Ph	p-BrC6H4	67
20	3t	p-CH3C6H4	Ph	Ph	43
21	3u	p-CH3C6H4	Ph	p-CH3OC6H4	37
22	3v	p-CH3C6H4	Ph	p-BrC6H4	32

Reaction conditions: α,β-unsaturated N-arylaldimine (1.1 mmol), 2-arylidene-1,3-indanedione (2.0 mmol), CH3CN (10.0 mL), 60 °C, 10 h, N2, in Schenk tube.

Isolated yields.

The above three-molecular reaction usually afforded only one diastereoisomer, which obviously indicated the reaction proceeding with the one-step Diels–Alder reaction. For determining the relative configuration of the obtained products, the single crystal structures of the compounds 3e (Figure ), 3g, 3i, 3l, and 3p (Figures s1–s4) were successfully determined by the X-ray diffraction method. It was pleasing to find that the same relative configuration was observed in the five single crystals. From Figure , it can be seen that the two aryl groups at 2,4-positions exist on the cis-positions in the newly formed tetrahydropyridyl ring, while the third aryl group in the newly formed pyran ring also stands on the cis-position to that of the other two aryl groups. The dihydropyranyl ring fused to the pyrrolidinyl ring from the endo-direction. Thus, on the basis of 1H NMR spectra and single crystal structures, it can be concluded that all spiropolycylces 3a–3v have this kind of 5,6,8-cis/cis-configuration. It should be pointed out that this kind of configuration is the same as our previously prepared polycyclic compounds derived from the reaction of α,β-unsaturated N-arylaldimines with 5-arylidene-1,3-dimethylbarbituric acids. This result clearly showed that this domino aza/oxa-Diels–Alder reaction of α,β-unsaturated N-arylaldimines with cyclic dienophiles has the same outcome of stereoselectivity.

Figure 2

Single crystal structure of the compound 3g.

For developing the scope of this reaction, α,β-unsaturated N-benzylaldimines were also employed in the reaction. The reaction of various α,β-unsaturated N-benzylaldimines and 2-arylidene-1,3-indanediones in acetonitrile at room temperature gave the desired spiropolycycles 4a–4r in satisfactory yields. However, the reaction at the elevated temperature resulted in lower yields of products, which might be due to the relative instability of α,β-unsaturated N-benzylaldimines to that of N-arylaldimines. The results are summarized in Table . It can be seen that benzylamine and its p-CH3O, p-CH3, p-Cl, and p-Br derivatives can be successfully used in the reaction. Additionally, α,β-unsaturated N-butylaldimine also reacted smoothly to give the spirocyclic compounds 4q and 4r in good yields. 2-Arylidene-1,3-indanediones with moderate electron-donating methyl groups and electron-withdrawing halo groups (F, Cl, and Br) can be successfully employed in the reaction. 2-Arylidene-1,3-indanediones with strong electron-donating groups, such as the methoxy group, does not take place because these substituents decrease the electrophilic character of the 2-arylidenedione framework in the polar Diels–Alder reactions.[21]1H and 13C NMR spectra clearly indicated that there is only one diastereoisomer existing in the obtained samples. For example, in the 1H NMR spectrum of compound 4b, the CH2 protons of the benzyl group showed two doublets at 3.98 ad 3.85 ppm with the germinal coupling constants J = 14.0 Hz. The five CH units in the middle bicyclic ring of pyrano[2,3-b]pyridine gave two doublets at 5.37 and 4.94 ppm, mixed peaks at 3.74–3.63 ppm, and a singlet at 3.55 ppm. The single crystal structures of the compounds 4f (Figure ) and 4m (Figure s5) were determined by X-ray diffraction. From the figures, it can be seen that they have the same relative configuration to that of the above-mentioned five compounds, in which the three aryl groups exist on the cis-positions and the fused pyrano[2,3-b]pyridine] stretched to the endo-direction. Therefore, the spiropolycycles 3a–3v and 4a–4r have the same relative configuration and were obviously formed via the same diastereoselective reaction pathway.

Table 3

Synthesis of Spiropolycycles 4a–4r via the Aza/Oxa-Diels–Alder Reactiona

entry	compd	Ar1	Ar2	R	yield (%)b
1	4a	Ph	Ph	Bn	72
2	4b	Ph	Ph	p-ClC6H4CH2	68
3	4c	p-ClC6H4	Ph	Bn	72
4	4d	p-ClC6H4	Ph	p-CH3OC6H4CH2	64
5	4e	p-ClC6H4	Ph	p-ClC6H4CH2	80
6	4f	p-ClC6H4	Ph	p-BrC6H4CH2	82
7	4g	p-ClC6H4	p-ClC6H4	Bn	76
8	4h	p-ClC6H4	p-CH3OC6H4	Bn	73
9	4i	m-FC6H4	Ph	p-CH3C6H4CH2	67
10	4j	m-FC6H4	Ph	p-CH3OC6H4CH2	64
11	4k	m-FC6H4	Ph	p-ClC6H4CH2	63
12	4l	m-FC6H4	Ph	p-BrC6H4CH2	73
13	4m	p-BrC6H4	Ph	Bn	78
14	4n	p-CH3C6H4	Ph	p-CH3C6H4CH2	60
15	4o	p-CH3C6H4	Ph	p-ClC6H4CH2	65
16	4p	m-CH3C6H4	Ph	p-ClC6H4CH2	60
17	4q	m-FC6H4	Ph	n-C4H9	76
18	4r	p-BrC6H4	Ph	n-C4H9	62

Reaction conditions: α,β-unsaturated N-alkylaldimine (2.0 mmol), 2-arylidene-1,3-indanedione (1.1 mmol), CH3CN (10.0 mL), rt, 16 h, N2, in Schenk tube.

Isolated yields.

Figure 3

Single crystal structure of the compound 4f.

For explaining the reaction mechanism and stereochemistry, a plausible reaction mechanism was proposed in Scheme on the basis of the previously reported reactions[19,21,22] and the obtained experiments. First, an aza-Diels–Alder reaction between 1,4-aryl-1-aza-1,3-butadiene and one molecule of 2-arylidene-1,3-indanedione according to endo-transition state (A) afford terahydropyridine (B).[22] Both the aryl groups exist on the cis-positions in the intermediate (B). Then, an oxa-Diels–Alder reaction of the intermediate (B) with another molecule of 2-arylidene-1,3-indanedione via the endo-transition state (A) gave spiropolycycle 3 or 4, in which the three aryl group exist on cis-positions. In this domino reaction, 1,4-aryl-1-aza-1,3-butadiene successfully acted as an active diene to finish the aza-Diels–Alder reaction, and the initially formed terahydropyridine successfully played as an electron-rich dienophile to finish the oxa-Diels–Alder reaction. On the other hand, 5-arylidene-1,3-indanedione not only acted as an active dienophile, but also played as a useful 1-oxa-1,4-diene to the finish sequential aza-/oxa-Diels–Alder reaction. Therefore, the reactivity matching of the two substrates played a key role for this domino aza-/oxa-Diels–Alder reaction.

Scheme 1

Proposed Concerted Reaction Mechanism

In the investigation process of the above domino aza/oxa-Diels–Alder reaction, 2,2′-(arylmethylene)bis(1,3-indenediones), which were the byproduct of the base-catalyzed condensation reaction of aromatic aldehydes with 1,3-indanedione for the preparation of 2-arylidene-1,3-indanediones, reacted with α,β-unsaturated N-alkylaldimines in acetonitrile at room temperature to give 2′,4′-diaryl-6′-(arylamino)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraones (Table ). All reactions proceeded smoothly to give dispiro compounds 5a–5n in very high yields. Because there are three chiral carbon atoms in the dispiro compounds, a couple of diastereoisomers might be formed in the reaction. 1H NMR spectra clearly indicated that two main diastereoisomers with broad molecular ratios of 85:15 to 45:55 exist in the products. By analysis of the stable conformations of 1,3,5-trisubstituted cyclohexane derivatives, the 1,3,5-cis/cis-diastereoisomer was assigned as the most stable isomer because the three substituents exist in the equatorial positions, and the 1,3,5-trans/cis-diastereoisomer was assigned as a less stable isomer, in which one aryl group and arylamino group stand in equatorial positions and the other group exists in the axial position (Scheme ). The single crystal structures of the compounds 5g and 5i were successfully determined by X-ray diffraction. It can be seen that compound 5g belongs to the 1,3,5-cis/cis-configuration (Figure ). Compound 5i has a 1,3,5-trans/cis-configuration and the cyclohexyl ring exists in a twist-boat conformation because the bigger o-bromophenyl group in axial position is unstable (Figure s6).

Table 4

Synthesis of Dispirocyclohexanes 5a–5n via the Domino Cyclization Reactiona

entry	compd	Ar1	Ar2	Ar3	yield (%)b
1	5a	Ph	Ph	Ph	86 (70:30)
2	5b	p-CH3C6H4	Ph	Ph	89 (45:55)
3	5c	o-FC6H4	Ph	Ph	92 (70:30)
4	5d	o-FC6H4	Ph	m-ClC6H4	90 (75:25)
5	5e	o-ClC6H4	Ph	Ph	88 (40:60)
6	5f	o-ClC6H4	Ph	m-ClC6H4	91 (33:67)
7	5g	o-ClC6H4	Ph	p-CH3OC6H4	88 (78:22)
8	5h	p-BrC6H4	Ph	Ph	87 (65:35)
9	5i	o-BrC6H4	Ph	Ph	90 (35:65)
10	5j	o-BrC6H4	Ph	p-CH3C6H4	92 (80:20)
11	5k	o-BrC6H4	Ph	p-CH3OC6H4	90 (80:20)
12	5l	o-BrC6H4	p-CH3C6H4	p-CH3OC6H4	93 (75:25)
13	5m	o-BrC6H4	p-CH3OC6H4	p-CH3OC6H4	88 (85:15)
14	5n	o-BrC6H4	p-FC6H4	p-CH3OC6H4	85 (85:15)

Reaction conditions: α,β-unsaturated N-alkylaldimine (0.5 mmol), 2,2′-(arylmethylene)bis(indene-1,3-dione) (0.5 mmol), CH3CN (10.0 mL), rt, 4 h, N2, in Schenk tube.

Isolated yields.

Scheme 2

Illustration of the Two Main Isomers of Dispiro Compounds

Figure 4

Single crystal structures of compound 5g.

A plausible reaction mechanism is also proposed for the formation of the dispiro compounds (Scheme ). In polar solvent, 2,2′-(arylmethylene)bis(1,3-indenedione) equilibrates with its dienol tautomer (D) via the keto–enol tautomerization. Second, the Michael addition of enol (D) to α,β-unsaturated N-alkylaldimine resulted in the intermediate (E), which equilibrates with imine (F) via enamino–imine tautomerization. Finally, the intramolecular nucleophilic addition of enol to the imine afforded dispiro compound 5. In the final formation of the cyclohexane ring, the thermodynamically stable conformations were obviously formed as the main diastereoisomers. Here, a formal [3 + 3] cycloaddition reaction was successfully finished by the sequential nucleophilic 1,4-/1,2-additions.

Scheme 3

Plausible Formation Mechanism for Dispiro Compound 5

Conclusions

In summary, we have investigated the domino reaction of α,β-unsaturated aldimines with 2-arylidene-1,3-indenediones and 2,2′-(arylmethylene)bis(1,3-indenediones) and have provided efficient synthetic protocols for polysubstituted spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridines] and dispiro[indene-2,1′-cyclohexane-3′,2″-indenes]. The reaction has the advantages of using readily available reagents, catalyst-free, mild conditions, molecular diversity, good yields, and high diastereoselectivity. The versatile reactivity of α,β-unsaturated aldimines were sufficiently developed, in which it not only acted as active dienophile to accomplish the aza-Diels–Alder reaction, but also acted as dipolarophiles to finish the nucleophilic 1,2-/1,4-addition reaction. Therefore, this domino reaction might be found potential applications in organic and medicinal chemistry.

Experimental Section

General Information

Unless otherwise noted, all reactants or reagents including dry solvents were obtained from commercial suppliers and used as received. Analytical TLC was carried out using 0.25 mm commercial silica gel plates (Merck silica gel 60 F254). The developed chromatogram was analyzed by a UV lamp (254 nm). 1H NMR and 13C NMR spectra were obtained on a Variance 400 M. Chemical shifts (δ) are expressed in parts per million and are internally referenced. IR spectra were taken on a PerkinElmer spectrum 100 FTIR and are reported in reciprocal centimeters (cm–1). HRMS were obtained on an AB 5800 MALDI-TOF/TOF and are reported as m/z (relative intensity, TOF). Single crystals were obtained by slowly evaporating the compounds in the mixture of chloroform and ethanol. X-ray crystallographic data were collected using a SMART APEX II X-ray diffractometer. Melting points were measured on a Yanaco micro melting point apparatus and are uncorrected. The starting materials α,β-unsaturated N-aryl or N-alkylaldimines,[23] 2-arylidene-1,3-indanediones,[24] and 2,2′-(arylmethylene)bis(1,3-indenediones)[25] were prepared according to the literature methods.

General Procedure for the Synthesis of Polycyclic Compounds 3a–3v

Under a N2 atmosphere, a mixture of α,β-unsaturated N-arylaldimine (1.1 mmol) and 2-arylidene-1,3-indanedione (2.0 mmol) in dry acetonitrile (10.0 mL) was added in a Schlenk tube. The mixture was stirred at 60 °C for 6 h. The solvent was removed by rotatory evaporation at reduced pressure. The residue was subjected to silicon column chromatography with mixed petroleum ether and ethyl acetate (v/v = 6:1 to 10:1) as an eluant to give a pure product for analysis.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(4-bromophenyl)-1′-(4-methoxyphenyl)-4′-(p-tolyl)-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3a)

The product is obtained as a yellow solid, 82%, 0.719 g, mp 161–163 °C; 1H NMR (400 MHz, CDCl3): δ 7.51 (d, J = 7.6 Hz, 1H), 7.47–7.31 (m, 9H), 7.11 (t, J = 8.2 Hz, 3H), 7.02 (d, J = 8.4 Hz, 2H), 6.93–6.90 (m, 2H), 6.85 (s, 2H), 6.80–6.76 (m, 3H), 6.68 (d, J = 8.8 Hz, 2H), 5.62 (s, 1H), 5.44 (s, 1H), 3.92 (d, J = 12.4 Hz, 1H), 3.70 (m, 4H, CH), 3.58 (s, 1H), 2.10 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): δ 201.0, 200.9, 192.4, 175.0, 156.9, 151.5, 145.0, 142.8, 142.1, 141.1, 139.7, 137.5, 137.3, 135.3, 135.0, 134.5, 133.3, 132.3, 131.9, 131.8, 130.9, 130.8, 130.4, 130.2, 129.8, 129.4, 129.4, 128.7, 128.4, 126.1, 123.0, 122.8, 122.7, 122.3, 122.0, 121.3, 121.2, 120.7, 118.4, 113.7, 105.5, 93.8, 62.9, 62.5, 55.1, 45.3, 40.8, 34.9, 20.8; IR (KBr) ν: 3052, 2949, 2833, 1904, 1740, 1701, 1631, 1592, 1504, 1475, 1412, 1364, 1246, 1182, 1070, 1016, 955, 876, 819, 783, 742, 718, 639 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C49H36Br2NO5 ([M + H]+), 878.0940; found, 878.0951.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(4-bromophenyl)-1′,4′-bis(4-methoxyphenyl)-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3b)

The product is obtained as a yellow solid, 86%, 0.751 g, mp 133–135 °C; 1H NMR (400 MHz, CDCl3): δ 7.51 (d, J = 7.2 Hz, 1H), 7.48–7.31 (m, 8H), 7.28 (s, 1H), 7.18–7.15 (m, 1H), 7.10 (d, J = 8.8 Hz, 2H), 7.03 (d, J = 8.0 Hz, 2H), 6.91 (d, J = 8.4 Hz, 1H), 6.86–6.84 (m, 3H), 6.77 (d, J = 8.4 Hz, 1H), 6.69–6.66 (m, 3H), 6.54–6.51 (m, 1H), 5.62 (d, J = 2.0 Hz, 1H), 5.44 (s, 1H), 3.90 (d, J = 14.4 Hz, 1H), 3.70 (s, 3H), 3.66 (d, J = 13.2 Hz, 1H), 3.63 (s, 3H), 3.59 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 200.8, 200.7, 192.3, 174.9, 163.2, 160.8, 157.0, 142.6, 141.8, 141.0, 139.5, 137.2, 135.6, 135.3, 134.3, 133.7, 133.6, 133.3, 132.0, 131.9, 131.4, 131.3, 131.0, 130.9, 130.8, 130.5, 130.3, 129.8, 129.4, 128.3, 127.9, 127.8, 122.4, 122.2, 122.1, 121.4, 121.3, 120.9, 118.5, 115.9, 115.8, 115.7, 115.6, 114.4, 113.7, 105.3, 93.7, 62.8, 62.4, 55.1, 44.9, 40.6, 35.0; IR (KBr) ν: 3070, 2918, 2847, 1891, 1741, 1700, 1627, 1596, 1510, 1476, 1414, 1369, 1250, 1183, 1075, 1024, 953, 822, 743 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C49H36Br2NO6 ([M + H]+), 894.0889; found, 894.0893.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(4-bromophenyl)-4′-(4-fluorophenyl)-1′-(4-methoxyphenyl)-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3c)

The product is obtained as a yellow solid, 71%, 0.626 g, mp 114–116 °C; 1H NMR (400 MHz, CDCl3): δ 7.52–7.32 (m, 9H), 7.25–7.23 (m, 1H), 7.10 (d, J = 8.8 Hz, 2H), 7.02 (d, J = 8.4 Hz, 2H), 6.94–6.91 (m, 2H), 6.87–6.82 (m, 3H), 6.78–6.67 (m, 5H), 5.63 (d, J = 1.6 Hz, 1H), 5.44 (s, 1H), 3.92 (d, J = 12.8 Hz, 1H), 3.73–3.70 (m, 4H), 3.55 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.1, 201.0, 192.4, 175.0, 158.9, 156.9, 142.8, 142.1, 141.1, 139.7, 137.3, 135.4, 135.1, 134.5, 133.3, 133.1, 131.9, 131.8, 130.9, 130.9, 130.8, 130.4, 130.3, 129.4, 128.3, 127.3, 127.2, 122.3, 122.0, 121.3, 121.2, 120.8, 118.4, 114.8, 113.7, 113.5, 105.5, 93.8, 62.9, 62.4, 55.1, 55.0, 44.9, 40.9, 34.8; IR (KBr) ν: 3064, 2947, 2837, 1895, 1740, 1701, 1631, 1594, 1504, 1413, 1366, 1240, 1189, 1073, 1008, 954, 876, 825, 743, 636 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H33Br2FNO5 ([M + H]+), 882.0689; found, 882.0693.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(4-bromophenyl)-1′-(4-methoxyphenyl)-4′-(4-nitrophenyl)-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3d)

The product is obtained as a yellow solid, 65%, 0.590 g, mp 148–150 °C; 1H NMR (400 MHz, CDCl3): δ 7.57–7.30 (m, 12H), 7.27 (s, 1H), 7.17 (t, J = 7.8 Hz, 1H), 7.09 (d, J = 8.8 Hz, 2H), 7.03 (d, J = 8.4 Hz, 2H), 6.91–6.88 (m, 1H), 6.84–6.77 (m, 2H), 6.73–6.67 (m, 3H), 5.65 (d, J = 2.0 Hz, 1H), 5.40 (s, 1H), 4.70 (d, J = 12.4 Hz, 1H), 4.07 (d, J = 13.2 Hz, 1H), 2.70 (s, 3H), 3.61 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 200.9, 199.7, 192.6, 174.5, 157.1, 152.0, 142.7, 141.7, 140.5, 139.4, 137.2, 135.7, 135.4, 133.9, 133.3, 132.1, 131.9, 131.9, 130.9, 130.9, 130.6, 130.2, 130.2, 129.4, 128.8, 128.5, 128.4, 125.2, 122.8, 122.0, 121.5, 121.3, 121.0, 118.4, 113.8, 105.7, 93.1, 63.3, 62.7, 55.2, 40.7, 38.8, 35.4; IR (KBr) ν: 3073, 2919, 2850, 1889, 1740, 1699, 1631, 1595, 1522, 1478, 1415, 1359, 1285, 1244, 1193, 1073, 1017, 956, 821, 754, 705 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H33Br2N2O7 ([M + H]+), 909.0634; found, 909.0633.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(4-bromophenyl)-1′,4′-diphenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3e)

The product is obtained as a yellow solid, 79%, 0.657 g, mp 134–136 °C; 1H NMR (400 MHz, CDCl3): δ 7.51–7.49 (m, 1H), 7.47–7.31 (m, 9H), 7.26–7.24 (m, 1H), 7.17–7.13 (m, 5H), 7.05–6.99 (m, 5H), 6.94–6.92 (m, 2H), 6.83–6.81 (m, 3H), 5.74 (d, J = 2.4 Hz, 1H), 5.54 (s, 1H), 3.99–3.96 (m, 1H), 3.72 (d, J = 13.2 Hz, 1H), 3.60 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 200.9, 200.7, 192.3, 174.9, 146.9, 142.7, 142.0, 141.0, 137.2, 135.4, 135.3, 135.1, 134.4, 133.3, 132.1, 132.0, 131.8, 131.0, 130.9, 130.7, 130.5, 130.3, 129.4, 128.9, 128.6, 128.0, 127.1, 126.2, 125.3, 122.3, 122.1, 121.3, 121.2, 120.8, 118.5, 105.5, 93.6, 62.8, 61.9, 45.8, 40.5, 35.0; IR (KBr) ν: 3034, 1742, 1701, 1632, 1593, 1487, 1415, 1370, 1249, 1193, 1073, 1009, 955, 878, 821, 761, 707, 658 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C47H32Br2NO4 ([M + H]+), 832.0698; found, 832.0683.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(4-bromophenyl)-1′-(4-methoxyphenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3f)

The product is obtained as a yellow solid, 86%, 0.741 g, mp 134–136 °C; 1H NMR (400 MHz, CDCl3): δ 7.50 (d, J = 7.2 Hz, 1H), 7.47–7.40 (m, 6H), 7.38–7.33 (m, 2H), 7.30 (d, J = 10.8 Hz, 1H), 7.26–7.25 (m, 1H), 7.15–7.10 (m, 3H), 7.04–6.99 (m, 4H), 6.92 (d, J = 8.0 Hz, 2H), 6.86 (s, 2H), 6.78 (d, J = 8.4 Hz, 1H), 6.68 (d, J = 8.8 Hz, 2H), 5.64 (d, J = 2.0 Hz, 1H), 5.46 (s, 1H), 3.95 (d, J = 12.8 Hz, 1H), 3.73–3.70 (m, 4H), 3.59 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 1200.9, 200.8, 192.3, 175.0, 157.0, 142.7, 142.0, 141.0, 139.7, 137.3, 135.4, 135.4, 135.0, 134.4, 133.3, 132.0, 131.9, 131.8, 131.0, 130.9, 130.9, 130.4, 130.3, 129.4, 128.9, 128.6, 128.3, 128.0, 126.2, 122.3, 122.0, 121.3, 121.2, 120.8, 118.4, 113.7, 105.5, 93.8, 62.8, 62.3, 55.1, 45.8, 40.6, 35.0; IR (KBr) ν: 3034, 2955, 2834, 1741, 1700, 1631, 1593, 1506, 1480, 1416, 1372, 1246, 1191, 1074, 1010, 954, 878, 821, 767, 702, 654 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H34Br2NO5 ([M + H]+), 862.0804; found, 862.0803.

(2′S,4′R,4a′S,5′S,11a′S)-1′,2′,5′-Tris(4-bromophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3g)

The product is obtained as a yellow solid, 82%, 748 g, mp 132–134 °C; 1H NMR (400 MHz, CDCl3): δ 7.51–7.49 (m, 1H), 7.47–7.42 (m, 5H), 7.41–7.32 (m, 3H), 7.29 (d, J = 8.4 Hz, 2H), 7.25–7.22 (m, 2H), 7.15–7.11 (m, 1H), 7.04–6.99 (m, 6H), 6.97–6.86 (m, 3H), 6.81 (d, J = 8.4 Hz, 2H), 5.66 (d, J = 2.4 Hz, 1H), 5.46 (s, 1H), 3.96–3.93 (m, 1H), 3.69 (d, J = 12.8 Hz, 1H), 3.60 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 200.7, 200.6, 192.2, 174.6, 146.1, 142.6, 141.9, 141.0, 137.1, 135.5, 135.2, 135.1, 134.0, 133.1, 132.0, 131.9, 131.8, 131.3, 130.9, 130.7, 130.6, 130.4, 129.4, 128.9, 128.6, 128.6, 128.1, 126.2, 122.4, 122.1, 121.6, 121.3, 120.9, 118.7, 118.4, 105.6, 93.2, 62.6, 61.8, 45.7, 40.5, 34.9; IR (KBr) ν: 3033, 1896, 1741, 1700, 1633, 1592, 1485, 1413, 1371, 1245, 1191, 1073, 1008, 955, 878, 822, 764, 709, 645 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C47H31Br3NO4 ([M + H]+), 911.9783; found, 911.9810.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(4-nitrophenyl)-1′,4′-diphenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3h)

The product is obtained as a yellow solid, 75%, 574 g, mp 147–149 °C; 1H NMR (400 MHz, CDCl3): δ 8.21 (d, J = 8.8 Hz, 2H), 7.70–7.68 (m, 1H), 7.60–7.57 (m, 1H), 7.52–7.34 (m, 10H), 7.27 (d, J = 8.8 Hz, 1H), 7.19–7.14 (m, 7H), 7.05–7.02 (m, 3H), 6.97–6.94 (m, 1H), 5.73–5.72 (m, 2H), 4.03 (d, J = 12.8 Hz, 1H), 3.79 (d, J = 12.8 Hz, 1H), 3.75 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 200.3, 200.3, 192.1, 175.0, 150.3, 147.1, 146.8, 146.4, 142.8, 142.4, 140.8, 136.9, 135.8, 135.5, 134.7, 133.0, 132.2, 132.1, 130.6, 130.2, 130.1, 129.1, 128.9, 128.8, 128.6, 128.4, 126.9, 126.0, 125.8, 124.1, 122.8, 122.7, 122.5, 122.2, 121.5, 118.7, 104.8, 93.2, 62.5, 62.0, 45.8, 40.5, 35.5; IR (KBr) ν: 3070, 2948, 2854, 1946, 1740, 1700, 1635, 1595, 1521, 1418, 1345, 1285, 1245, 1195, 1115, 1073, 1007, 957, 855, 759, 703 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C47H32N3O8 ([M + H]+), 766.2189; found, 766.2196.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Methoxyphenyl)-2′,5′-bis(4-nitrophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3i)

The product is obtained as a yellow solid, 80%, 0.637 g, mp 149–151 °C; 1H NMR (400 MHz, CDCl3): δ 8.20 (d, J = 8.4 Hz, 2H), 7.70–7.67 (m, 1H), 7.62–7.59 (m, 1H), 7.52–7.31 (m, 11H), 7.22–7.11 (m, 5H), 7.06–7.02 (m, 2H), 6.95 (s, 1H), 6.68 (d, J = 8.8 Hz, 2H), 5.64–5.63 (m, 2H), 4.01 (d, J = 12.4 Hz, 1H), 3.78 (d, J = 12.8 Hz, 1H), 3.74 (s, 1H), 3.66 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 200.4, 200.3, 192.1, 175.1, 157.3, 150.3, 147.1, 146.7, 142.8, 142.4, 140.8, 139.1, 137.0, 135.8, 135.5, 134.8, 133.1, 132.2, 132.1, 130.6, 130.3, 130.2, 129.1, 128.8, 128.6, 128.4, 128.2, 126.0, 124.1, 122.8, 122.7, 122.5, 122.2, 121.5, 118.7, 114.0, 104.8, 93.4, 62.6, 62.4, 55.2, 45.9, 40.5, 35.5; IR (KBr) ν: 3071, 2944, 2835, 1741, 1702, 1635, 1596, 1517, 1461, 1420, 1346, 1289, 1243, 1192, 1109, 1073, 1006, 956, 846, 756, 701, 657 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H34N3O9 ([M + H]+), 796.2295; found, 796.2287.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Bromophenyl)-2′,5′-bis(4-nitrophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3j)

The product is obtained as a yellow solid, 71%, 0.599 g, mp 151–153 °C; 1H NMR (400 MHz, CDCl3): δ 8.21 (d, J = 8.4 Hz, 2H), 7.73–7.70 (m, 1H), 7.64–7.62 (m, 1H), 7.52–7.40 (m, 7H), 7.35–7.28 (m, 5H), 7.24 (s, 1H), 7.19–713 (m, 3H), 7.05–7.03 (m, 4H), 6.92 (s, 1H), 5.65 (s, 2H), 4.01 (d, J = 13.2 Hz, 1H), 3.78–3.74 (m, 2H); 13C NMR (100 MHz, CDCl3): δ 200.2, 200.1, 192.0, 174.7, 150.1, 147.1, 146.9, 145.6, 142.4, 142.3, 140.8, 136.8, 135.9, 135.6, 134.5, 132.9, 132.3, 132.1, 130.7, 130.2, 130.0, 129.2, 128.8, 128.6, 128.5, 128.4, 125.9, 124.1, 123.1, 122.9, 122.5, 122.2, 121.6, 119.4, 118.7, 104.9, 92.8, 62.4, 61.8, 45.8, 40.4, 35.4; IR (KBr) ν: 3071, 2955, 1741, 1702, 1635, 1595, 1520, 1483, 1417, 1347, 1286, 1246, 1192, 1072, 1004, 952, 848, 803, 763, 704 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C47H31BrN3O8 ([M + H]+), 844.1295; found, 844.1307.

(2′R,4′R,4a′R,5′R,11a′S)-2′,5′-Bis(2-chlorophenyl)-1′-(4-methoxyphenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3k)

The product is obtained as a yellow solid, 76%, 0.588 g, mp 154–156 °C; 1H NMR (400 MHz, CDCl3): δ 7.65 (d, J = 7.1 Hz, 1H), 7.48–7.35 (m, 9H), 7.19–6.93 (m, 10H), 6.85 (s, 1H), 6.66–6.62 (m, 4H), 6.08 (s, 1H), 5.69 (s, 1H), 4.16 (d, J = 12.8 Hz, 1H), 3.83 (d, J = 12.8 Hz, 2H), 3.67 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 202.1, 198.3, 191.9, 175.8, 157.0, 143.4, 141.2, 140.0, 139.3, 137.3, 135.1, 134.9, 134.6, 133.9, 133.6, 133.4, 133.0, 132.5, 132.0, 131.4, 130.5, 130.4, 130.0, 129.4, 128.7, 128.3, 128.1, 128.0, 127.9, 127.8, 126.6, 126.1, 122.6, 122.0, 121.3, 118.5, 113.7, 105.5, 94.6, 62.0, 58.6, 55.2, 46.8, 37.7, 33.6; IR (KBr) ν: 3061, 2920, 1897, 1743, 1702, 1632, 1590, 1510, 1461, 1419, 1371, 1241, 1192, 1072, 1010, 951, 871, 823, 755, 619 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H34Cl2NO5 ([M + H]+), 774.1814; found, 774.1846.

(2′R,4′R,4a′R,5′R,11a′S)-2′,5′-Bis(2-bromophenyl)-4′-phenyl-1′-(p-tolyl)-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3l)

The product is obtained as a yellow solid, 85%, 0.721 g, mp 159–161 °C; 1H NMR (400 MHz, CDCl3): δ 7.67 (d, J = 8.0 Hz, 1H), 7.60 (d, J = 8.5 Hz, 1H), 7.48–7.35 (m, 8H), 7.12–6.78 (m, 13H), 6.65 (t, J = 8.1 Hz, 1H), 6.55–6.51 (m, 1H), 6.07 (s, 1H), 5.76 (s, 1H), 4.17 (d, J = 12.5 Hz, 1H), 3.86–3.81 (m, 2H), 2.17 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 202.2, 198.0, 191.8, 175.7, 144.5, 143.4, 141.3, 140.9, 137.3, 135.1, 134.9, 134.6, 134.5, 134.0, 133.4, 133.0, 132.6, 132.0, 131.6, 130.4, 130.3, 129.2, 128.9, 128.7, 128.4, 127.9, 127.8, 127.2, 127.0, 126.7, 124.6, 124.3, 122.6, 122.1, 121.3, 118.4, 110.0, 105.7, 94.6, 61.9, 61.2, 46.9, 37.7, 35.9, 20.9; IR (KBr) ν: 3035, 2913, 2836, 2332, 1876, 1700, 1630, 1593, 1507, 1459, 1418, 1367, 1241, 1185, 1030, 958, 874, 830, 763, 702, 636 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H34Br2NO4 ([M + H]+), 848.0834; found, 848.0863.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(3-chlorophenyl)-1′,4′-diphenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3m)

The product is obtained as a yellow solid, 73%, 0.543 g, mp 163–165 °C; 1H NMR (400 MHz, CDCl3): δ 7.58–7.32 (m, 9H), 7.18 (t, J = 4.2 Hz, 5H), 7.12 (s, 1H), 7.05–7.01 (m, 4H), 6.96–6.93 (m, 2H), 6.83 (dd, J = 13.3, 7.0 Hz, 2H), 6.74–6.58 (m, 3H), 5.76–5.74 (m, 1H), 5.54, 5.51 (s, 1H), 4.08–4.01 (m, 1H), 3.76–3.72 (m, 1H), 3.63 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 200.8, 200.7, 200.6, 192.4, 175.0, 147.0, 146.7, 145.0, 145.0, 142.8, 142.7, 141.1, 141.0, 137.5, 137.4, 137.3, 135.5, 135.4, 135.4, 135.3, 135.1, 135.0, 134.7, 133.9, 133.3, 133.1, 132.2, 132.2, 132.1, 132.0, 130.4, 130.1, 129.2, 129.1, 128.9, 128.8, 128.7, 128.5, 128.1, 127.9, 127.8, 127.8, 127.6, 127.5, 127.4, 127.3, 127.3, 127.2, 127.1, 126.4, 126.0, 125.9, 125.5, 125.3, 122.4, 122.3, 122.1, 122.0, 121.3, 118.6, 105.3, 93.6, 93.5, 62.8, 62.8, 62.3, 62.2, 45.6, 40.6, 40.5, 35.3, 35.2; IR (KBr) ν: 3062, 2923, 2853, 1954, 1740, 1700, 1632, 1591, 1484, 1465, 1420, 1367, 1246, 1196, 1078, 1004, 954, 877, 757, 700 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C47H32Cl2NO4 ([M + H]+), 744.1708; found, 744.1709.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(3-chlorophenyl)-1′-(4-methoxyphenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3n)

The product is obtained as a yellow solid, 69%, 0.534 g, mp 168–170 °C; 1H NMR (400 MHz, CDCl3): δ 7.57 (d, J = 7.8 Hz, 1H), 7.47–7.28 (m, 9H), 7.14 (dd, J = 16.6, 8.4 Hz, 4H), 7.05–6.89 (m, 6H), 6.78 (d, J = 7.8 Hz, 1H), 6.79–6.66 (m, 5H), 5.65 (s, 1H), 5.47, 5.43 (s, 1H), 4.06–3.98 (m, 1H), 3.74 (s, 1H), 3.70 (d, J = 2.9 Hz, 3H), 3.62 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 200.8, 200.8, 200.7, 200.7, 192.4, 175.1, 157.1, 157.0, 145.1, 145.0, 142.8, 142.7, 141.1, 141.0, 139.7, 139.5, 137.5, 137.4, 137.3, 135.5, 135.5, 135.3, 135.1, 135.0, 134.6, 133.9, 133.3, 133.0, 132.2, 132.1, 132.0, 130.4, 130.1, 129.4, 129.3, 129.1, 128.9, 128.8, 128.7, 128.7, 128.5, 128.4, 128.0, 127.9, 127.8, 127.8, 127.5, 127.2, 127.2, 126.4, 126.0, 126.0, 122.4, 122.3, 122.0, 121.3, 118.6, 113.8, 113.8, 105.3, 93.8, 93.7, 62.9, 62.9, 62.7, 62.7, 55.2, 45.6, 40.6, 40.6, 35.3, 35.2; IR (KBr) ν: 3064, 2950, 2838, 1740, 1701, 1630, 1591, 1507, 1466, 1421, 1365, 1244, 1079, 1026, 953, 877, 833, 776, 748, 701 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H34Cl2NO5 ([M + H]+), 774.1814; found, 774.1790.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Bromophenyl)-2′,5′-bis(3-chlorophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3o)

The product is obtained as a yellow solid, 78%, 0.688 g, mp 130–132 °C; 1H NMR (400 MHz, CDCl3): δ 1H NMR (400 MHz, CDCl3): δ 7.56 (d, J = 7.6 Hz, 1H), 7.49–7.35 (m, 7H), 7.32–7.28 (m, 3H), 7.24 (d, J = 6.3 Hz, 2H), 7.18–7.14 (m, 1H), 7.11–7.01 (m, 6H), 6.93 (s, 2H), 6.83–6.79 (m, 1H), 6.76–6.67 (m, 2H), 5.68–5.66 (m, 2.0 Hz, 1H), 5.47, 5.44 (s, 1H), 4.05–3.98 (m, 1H), 3.71 (d, J = 13.0 Hz, 1H), 3.62 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 200.6, 200.6, 200.5, 192.3, 174.7, 146.1, 146.0, 144.9, 144.9, 142.8, 142.6, 141.1, 141.0, 137.1, 137.1, 137.1, 137.0, 135.6, 135.4, 135.2, 135.2, 135.2, 135.1, 134.7, 134.7, 134.2, 133.3, 133.2, 132.2, 132.1, 132.1, 131.9, 131.8, 130.5, 130.1, 130.1, 129.3, 129.2, 129.1, 129.0, 129.0, 128.9, 128.8, 128.8, 128.7, 128.7, 128.2, 128.1, 128.1, 127.8, 127.8, 127.5, 127.4, 127.3, 127.2, 126.3, 126.3, 125.9, 125.9, 122.4, 122.4, 122.1, 121.4, 119.0, 118.8, 118.5, 105.4, 105.4, 93.2, 93.2, 62.7, 62.7, 62.1, 62.1, 45.6, 40.5, 40.5, 35.2, 35.2, 30.3, 29.7; IR (KBr) ν: 3065, 2924, 2853, 1740, 1702, 1631, 1590, 1481, 1420, 1364, 1245, 1195, 1075, 1003, 951, 877, 830, 767, 701 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C47H31BrCl2NO4 ([M + H]+), 822.0814; found, 822.0822.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(3-fluorophenyl)-1′,4′-diphenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3p)

The product is obtained as a yellow solid, 68%, 0.484 g, mp 171–173 °C; 1H NMR (400 MHz, CDCl3): δ 1H NMR (400 MHz, CDCl3): δ 7.56–7.29 (m, 10H), 7.17 (s, 5H), 7.01–6.95 (m, 6H), 6.87 (d, J = 9.2 Hz, 1H), 6.78–6.66 (m, 3H), 6.40–6.39 (m, 1H), 5.77 (s, 1H), 5.59, 5.53 (s, 1H), 4.05 (d, J = 11.5 Hz, 1H), 3.74 (d, J = 12.5 Hz, 1H), 3.65 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 200.9, 200.9, 200.7, 200.7, 192.5, 175.0, 174.9, 164.3, 161.8, 147.1, 146.9, 145.6, 145.5, 142.8, 141.1, 138.1, 137.8, 137.3, 137.3, 135.4, 135.3, 135.1, 135.0, 133.3, 132.2, 132.1, 132.0, 132.0, 130.4, 130.3, 130.3, 129.4, 129.4, 129.1, 129.0, 128.9, 128.9, 128.7, 128.7, 128.7, 128.6, 128.0, 127.1, 126.4, 126.4, 125.4, 125.3, 125.1, 125.1, 124.9, 123.4, 123.3, 122.4, 122.3, 122.1, 122.0, 121.3, 118.6, 118.6, 116.6, 116.4, 116.2, 116.0, 114.9, 114.8, 114.7, 114.3, 114.1, 113.9, 113.8, 105.5, 105.5, 93.7, 62.8, 62.4, 62.1, 45.7, 45.7, 40.5, 35.3; IR (KBr) ν: 3062, 2907, 1954, 1742, 1701, 1634, 1590, 1475, 1417, 1369, 1245, 1184, 1075, 1007, 959, 874, 765, 701 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C47H32F2NO7 ([M + H]+), 712.2299; found, 712.2315.

(2′S,4′R,4a′S,5′S,11a′S)-1′,2′,4′,5′-Tetraphenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3q)

The product is obtained as a yellow solid, 53%, 0.358 g, mp 164–166 °C; 1H NMR (400 MHz, CDCl3): δ 7.47 (d, J = 7.2 Hz, 1H), 7.41–7.30 (m, 10H), 7.26–7.23 (m, 1H), 7.18–7.10 (m, 7H), 7.00–6.92 (m, 6H), 6.81–6.76 (m, 1H), 6.68–6.64 (m, 2H), 5.83 (d, J = 2.4 Hz, 1H), 5.57 (s, 1H), 4.09 (d, J = 13.2 Hz, 1H), 3.77 (d, J = 13.2 Hz, 1H), 3.67 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.2, 200.9, 192.6, 174.9, 147.3, 142.9, 142.9, 141.2, 137.5, 135.8, 135.3, 135.0, 134.6, 133.5, 132.1, 131.8, 130.1, 129.4, 129.0, 128.7, 128.5, 128.3, 127.8, 127.7, 127.3, 127.2, 126.8, 126.5, 124.9, 122.2, 121.9, 121.1, 118.4, 106.0, 93.9, 63.1, 62.7, 45.8, 40.6, 35.4; IR (KBr) ν: 3030, 2856, 1955, 1741, 1701, 1632, 1590, 1490, 1457, 1414, 1368, 1286, 1240, 1195, 1146, 1072, 1004, 949, 872, 761, 699, 623 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C47H34NO4 ([M + H]+), 676.2488; found, 676.2475.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Methoxyphenyl)-2′,4′,5′-triphenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3r)

The product is obtained as a yellow solid, 48%, 0.339 g, mp 153–155 °C; 1H NMR (400 MHz, CDCl3): δ 7.47 (d, J = 6.8 Hz, 1H), 7.43–7.29 (m, 10H), 7.26–7.22 (m, 1H), 7.17–7.12 (m, 5H), 7.00–6.94 (m, 4H), 6.90 (d, J = 7.6 Hz, 1H), 6.79–6.75 (m, 1H), 6.71–6.64 (m, 4H), 5.73 (d, J = 2.4 Hz, 1H), 5.50 (s, 1H), 4.06 (d, J = 13.2 Hz, 1H), 3.76 (d, J = 13.2 Hz, 1H), 3.67 (s, 3H), 3.66 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.2, 200.9, 192.6, 175.0, 156.7, 143.0, 142.9, 141.2, 140.2, 137.5, 135.8, 135.2, 134.9, 134.6, 133.5, 132.1, 131.8, 130.1, 129.5, 129.2, 128.7, 128.7, 128.5, 128.4, 127.7, 127.7, 127.3, 126.7, 126.5, 122.2, 121.9, 121.1, 118.3, 113.5, 106.0, 94.1, 63.1, 63.1, 55.1, 45.8, 40.6, 35.4; IR (KBr) ν: 3030, 2917, 2837, 1882, 1739, 1700, 1625, 1591, 1504, 1455, 1411, 1367, 1244, 1188, 1073, 1028, 955, 922, 878, 832, 766, 699, 625 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H36NO5 ([M + H]+), 706.2593; found, 706.2583.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Bromophenyl)-2′,4′,5′-triphenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3s)

The product is obtained as a yellow solid, 67%, 0.505 g, mp 116–118 °C; 1H NMR (400 MHz, CDCl3): δ 7.47 (d, J = 7.2 Hz, 1H), 7.43–7.37 (m, 5H), 7.34–7.31 (m, 5H), 7.24–7.22 (m, 2H), 7.17–7.12 (m, 3H), 7.04 (d, J = 8.8 Hz, 2H), 7.00 (t, J = 6.4 Hz, 2H), 6.95–6.88 (m, 4H), 6.82–6.78 (m, 1H), 6.72–6.70 (m, 2H), 5.76 (d, J = 2.0 Hz, 1H), 5.50 (s, 1H), 4.06 (d, J = 12.8 Hz, 1H), 3.75 (d, J = 12.8 Hz, 1H), 3.66 (s, 1H); 13C NMR (151 MHz, CDCl3): δ 201.0, 200.8, 192.5, 174.5, 147.0, 142.9, 141.2, 137.4, 135.6, 135.4, 135.2, 135.1, 134.9, 134.7, 134.1, 133.4, 133.2, 132.1, 131.9, 131.5, 130.2, 129.5, 128.9, 128.8, 128.8, 128.7, 128.6, 128.0, 127.9, 127.7, 127.6, 127.5, 126.9, 126.5, 123.3, 123.3, 122.2, 121.9, 121.2, 118.3, 118.3, 106.1, 93.5, 63.0, 62.5, 45.7, 40.5, 35.4, 29.7; IR (KBr) ν: 3062, 2921, 2852, 1740, 1701, 1630, 1591, 1487, 1458, 1412, 1365, 1245, 1193, 1073, 1002, 952, 877, 824, 763, 704, 629 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C47H33BrNO4 ([M + H]+), 754.1593; found, 754.1573.

(2′S,4′R,4a′S,5′S,11a′S)-1′,4′-Diphenyl-2′,5′-di-p-tolyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3t)

The product is obtained as a yellow solid, 43%, 0.302 g, mp 172–174 °C; 1H NMR (400 MHz, CDCl3): δ 7.45 (d, J = 6.8 Hz, 1H), 7.40–7.29 (m, 7H), 7.23 (d, J = 7.2 Hz, 1H), 7.17–7.09 (m, 7H), 7.04 (d, J = 8.0 Hz, 2H), 6.98–6.91 (m, 4H), 6.78 (t, J = 6.6 Hz, 2H), 6.55 (d, J = 7.2 Hz, 1H), 6.46 (d, J = 7.6 Hz, 1H), 5.82 (d, J = 2.0 Hz, 1H), 5.51 (s, 1H), 4.04 (d, J = 12.8 Hz, 1H), 3.73 (d, J = 13.2 Hz, 1H), 3.61 (s, 1H), 2.33 (s, 3H), 1.86 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 201.3, 201.0, 192.6, 174.7, 147.5, 142.9, 141.2, 140.0, 137.6, 136.8, 136.2, 135.9, 134.8, 134.5, 134.4, 133.5, 132.2, 132.1, 131.7, 130.0, 129.6, 129.4, 129.3, 128.8, 128.6, 128.5, 128.5, 128.2, 127.8, 127.7, 127.6, 127.2, 126.5, 124.7, 122.9, 122.1, 121.9, 121.0, 118.3, 106.3, 94.0, 63.2, 62.3, 45.8, 40.5, 35.1, 21.0, 20.7; IR (KBr) ν: 3031, 2856, 1740, 1701, 1632, 1591, 1499, 1459, 1416, 1368, 1247, 1195, 1073, 1007, 954, 876, 808, 757, 704, 603 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C49H38NO4 ([M + H]+), 704.2801; found, 704.2818.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Methoxyphenyl)-4′-phenyl-2′,5′-di-p-tolyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3u)

The product is obtained as a yellow solid, 37%, 271 g, mp 128–130 °C; 1H NMR (400 MHz, CDCl3): δ 7.47 (d, J = 7.2 Hz, 1H), 7.42–7.27 (m, 8H), 7.14–7.09 (m, 5H), 7.05–7.03 (m, 2H), 6.99–6.97 (m, 2H), 6.95–6.92 (m, 1H), 6.82–6.76 (m, 2H), 6.66 (d, J = 9.2 Hz, 1H), 6.55 (d, J = 7.2 Hz, 1H), 6.48 (d, J = 8.0 Hz, 1H), 5.72 (d, J = 2.4 Hz, 1H), 5.45 (s, 1H), 4.02 (d, J = 12.0 Hz, 1H), 3.73 (d, J = 12.4 Hz, 1H), 3.68 (s, 3H), 3.61 (s, 1H), 2.33 (s, 3H), 1.88 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 201.3, 201.0, 192.6, 174.8, 156.6, 143.0, 141.2, 140.3, 140.0, 137.6, 136.7, 136.2, 135.9, 134.8, 134.5, 133.5, 132.2, 132.1, 131.7, 130.0, 129.4, 129.3, 129.0, 128.6, 128.5, 128.4, 127.8, 127.6, 127.6, 126.5, 122.1, 121.9, 121.0, 118.3, 113.4, 106.2, 94.2, 63.2, 62.7, 55.1, 45.8, 40.6, 35.1, 21.0, 20.7; IR (KBr) ν: 3033, 2921, 2850, 1741, 1701, 1631, 1593, 1509, 1461, 1419, 1370, 1245, 1192, 1075, 1031, 955, 878, 817, 765, 709, 649, 606 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C50H40NO5 ([M + H]+), 734.2906; found, 734.2922.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Bromophenyl)-4′-phenyl-2′,5′-di-p-tolyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (3v)

The product is obtained as a yellow solid, 32%, 0.250 g, mp 149–151 °C; 1H NMR (400 MHz, CDCl3): δ 7.47 (d, J = 7.2 Hz, 1H), 7.41–7.34 (m, 6H), 7.33–7.28 (m, 3H), 7.24–7.21 (m, 2H), 7.12 (d, J = 7.6 Hz, 2H), 7.04 (d, J = 8.4 Hz, 4H), 7.00–6.98 (m, 2H), 6.93–6.91 (m, 1H), 6.80–6.75 (m, 2H), 6.58 (d, J = 8.0 Hz, 1H), 6.50 (d, J = 8.0 Hz, 1H), 5.74 (d, J = 2.0 Hz, 1H), 5.45 (s, 1H), 4.01 (d, J = 12.4 Hz, 1H), 3.71 (d, J = 12.4 Hz, 1H), 3.61 (s, 1H), 2.34 (s, 3H), 1.90 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 201.1, 200.9, 192.5, 174.4, 146.7, 142.9, 141.2, 139.9, 137.4, 137.1, 136.3, 135.6, 134.9, 134.6, 133.4, 132.1, 131.8, 131.4, 130.1, 129.4, 129.3, 128.8, 128.7, 128.7, 128.5, 128.0, 127.7, 127.5, 126.5, 122.2, 121.9, 121.1, 118.2, 118.1, 109.9, 106.3, 93.6, 63.0, 62.2, 45.7, 40.5, 35.0, 29.6, 21.0, 20.7; IR (KBr) ν: 3029, 2920, 2858, 1741, 1700, 1634, 1592, 1485, 1415, 1368, 1246, 1191, 1072, 1008, 957, 878, 812, 763, 708, cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C49H37BrNO4 ([M + H]+), 782.1906; found, 782.1910.

2-(3-(4-Methoxyphenyl)allylidene)-1H-indene-1,3(2H)-dione

The product is obtained as a yellow solid, 34%, mp 212–214 °C; 1H NMR (400 MHz, CDCl3): δ 8.37–8.30 (m, 1H), 7.96–7.94 (m, 2H), 7.80–7.76 (m, 2H), 7.65–7.62 (m, 3H), 7.31 (d, J = 15.4 Hz, 1H), 6.95 (d, J = 8.7 Hz, 2H), 3.87 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 190.74, 190.30, 162.14, 151.45, 145.39, 142.07, 140.76, 134.89, 134.76, 130.68, 128.47, 126.65, 122.94, 122.76, 121.68, 114.57, 55.46; IR (KBr) ν: 3042, 2990, 2845, 2718, 2563, 2031, 1858, 1747, 1679, 1578, 1508, 1461, 1367, 1303, 1257, 1214, 1163, 1022, 986, 864, 818, 733, 698, 601 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C19H15O3 ([M + H]+), 291.1021; found, 291.1002.

General Procedure for the Synthesis of Polycyclic Compounds 4a–4r

Under a N2 atmosphere, a mixture of α,β-unsaturated N-arylaldimine (1.1 mmol) and 2-arylidene-1,3-indanedione (2.0 mmol) in dry acetonitrile (10.0 mL) was added in a Schlenk tube. The mixture was stirred at room temperature for 24 h. The solvent was removed by rotatory evaporation at reduced pressure. The residue was subjected to silicon column chromatography with mixed petroleum ether and ethyl acetate (v/v = 8:1 to 12:1) as an eluant to give a pure product for analysis.

(2′S,4′R,4a′S,5′S,11a′S)-1′-Benzyl-2′,4′,5′-triphenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4a)

The product is obtained as a yellow solid, 72%, 0.497 g, mp 158–160 °C; 1H NMR (400 MHz, CDCl3): δ 7.50–7.45 (m, 2H), 7.43–7.32 (m, 9H), 7.27 (s, 1H), 7.25–7.19 (m, 3H), 7.14–7.06 (m, 4H), 6.96–6.87 (m, 9H), 5.45 (d, J = 2.0 Hz, 1H), 4.95 (s, 1H), 4.01–3.89 (m, 2H), 3.76–3.64 (m, 2H), 3.54 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.3, 192.6, 174.7, 143.0, 142.9, 141.2, 137.8, 137.0, 135.8, 135.7, 135.0, 134.7, 133.6, 132.0, 130.1, 128.7, 128.7, 128.6, 128.6, 128.5, 128.5, 128.4, 128.2, 127.7, 127.3, 127.2, 126.7, 126.6, 122.2, 121.9, 121.1, 118.2, 106.6, 90.1, 64.9, 63.5, 52.7, 45.7, 39.6, 35.4; IR (KBr) ν: 3030, 2920, 2859, 1958, 1883, 1816, 1738, 1701, 1632, 1593, 1492, 1457, 1409, 1385, 1361, 1249, 1194, 1071, 1022, 955, 887, 761, 701, 618 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H36NO4 ([M + H]+), 690.2644; found, 690.2652.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Chlorobenzyl)-2′,4′,5′-triphenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4b)

The product is obtained as a yellow solid, 68%, 0.492 g, mp 169–171 °C; 1H NMR (400 MHz, CDCl3): δ 7.48 (t, J = 8.5 Hz, 2H), 7.42–7.33 (m, 6H), 7.24–7.16 (m, 9H), 7.09 (br s, 1H), 6.96–6.86 (m, 9H), 5.37 (d, J = 2.4 Hz, 1H), 4.94 (d, J = 1.8 Hz, 1H), 3.98 (d, J = 14.0 Hz, 1H), 3.85 (d, J = 14.0 Hz, 1H), 3.74–3.63 (m, 2H), 3.55 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.3, 201.1, 192.5, 174.5, 142.9, 142.9, 141.2, 137.7, 135.7, 135.6, 135.5, 135.1, 134.8, 133.5, 132.9, 132.0, 132.0, 130.2, 129.9, 128.7, 128.6, 128.5, 128.5, 128.3, 128.2, 127.8, 127.3, 126.7, 126.6, 122.2, 121.9, 121.2, 118.2, 106.6, 90.0, 64.8, 63.4, 52.2, 45.6, 39.7, 35.4; IR (KBr) ν: 3029, 2944, 2860, 1960, 1822, 1735, 1696, 1629, 1590, 1489, 1458, 1414, 1378, 1276, 1177, 1080, 1016, 945, 895, 821, 764, 703, 659, 621 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H35ClNO4 ([M + H]+), 724.2255; found, 724.2266.

(2′S,4′R,4a′S,5′S,11a′S)-1′-Benzyl-2′,5′-bis(4-chlorophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4c)

The product is obtained as a yellow solid, 72%, 0.546 g, mp 132–134 °C; 1H NMR (400 MHz, CDCl3): δ 7.52–7.41 (m, 6H), 7.38–7.28 (m, 7H), 7.24 (d, J = 6.1 Hz, 1H), 7.16–7.06 (m, 4H), 6.96–6.94 (m, 5H), 6.88–6.84 (m, 3H), 5.36 (s, 1H), 4.93 (s, 1H), 3.97 (d, J = 13.7 Hz, 1H), 3.83 (d, J = 13.7 Hz, 1H), 3.63 (s, 2H), 3.50 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.1, 201.0, 192.4, 174.7, 142.8, 141.5, 141.1, 137.5, 136.6, 135.4, 135.3, 135.1, 134.3, 134.0, 133.4, 132.5, 132.1, 131.9, 130.3, 128.8, 128.7, 128.6, 128.6, 128.6, 128.5, 127.9, 127.4, 126.4, 122.4, 122.1, 121.3, 118.4, 106.2, 89.8, 64.1, 63.2, 52.8, 45.7, 39.5, 34.9; IR (KBr) ν: 3032, 2871, 1894, 1700, 1638, 1595, 1488, 1416, 1371, 1250, 1184, 1092, 1017, 948, 893, 822, 766, 707, 612 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H34Cl2NO4 ([M + H]+), 758.1865; found, 758.1878.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(4-chlorophenyl)-1′-(4-methoxybenzyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4d)

The product is obtained as a white solid, 64%, 0.504 g, mp 154–156 °C; 1H NMR (400 MHz, CDCl3): δ 7.52–7.42 (m, 9H), 7.20 (d, J = 8.0 Hz, 2H), 7.15–7.06 (m, 4H), 7.01–6.95 (m, 5H), 6.89–6.80 (m, 5H), 5.33 (s, 1H), 4.90 (s, 1H), 3.89–3.75 (m, 5H), 3.60 (s, 2H), 3.50 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.1, 201.1, 192.4, 174.8, 159.0, 142.8, 141.6, 141.1, 137.5, 135.4, 135.3, 135.1, 134.4, 133.9, 133.5, 132.4, 132.1, 131.9, 130.3, 130.0, 128.8, 128.7, 128.6, 128.5, 128.3, 127.9, 126.4, 122.3, 122.0, 121.3, 118.4, 113.9, 106.1, 89.7, 64.1, 63.3, 55.3, 52.3, 45.6, 39.6, 34.9; IR (KBr) ν: 3039, 2948, 2839, 1903, 1739, 1699, 1630, 1593, 1499, 1463, 1411, 1251, 1188, 1093, 1021, 950, 888, 823, 763, 708, 657, 609 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C49H36Cl2NO5 ([M + H]+), 788.1971; found, 788.1988.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Chlorobenzyl)-2′,5′-bis(4-chlorophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4e)

The product is obtained as a yellow solid, 80%, 0.634 g, mp 163–165 °C; 1H NMR (400 MHz, CDCl3): δ 7.53–7.34 (m, 8H), 7.25–7.22 (m, 4H), 7.16 (d, J = 8.2 Hz, 3H), 7.10–7.06 (m, 2H), 6.96 (d, J = 3.8 Hz, 5H), 6.89–6.85 (m, 3H), 5.29 (s, 1H), 4.92 (s, 1H), 3.98 (d, J = 14.4 Hz, 1H), 3.78 (d, J = 14.0 Hz, 1H), 3.65–3.58 (m, 2H), 3.51 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.2, 200.9, 192.3, 174.5, 142.8, 141.4, 141.0, 137.4, 135.5, 135.3, 135.3, 135.2, 135.2, 134.1, 134.1, 133.3, 133.2, 132.7, 132.1, 131.9, 130.4, 129.8, 129.1, 128.8, 128.7, 128.7, 128.6, 128.6, 128.0, 126.3, 122.4, 122.0, 121.4, 118.3, 106.2, 89.8, 64.1, 63.1, 52.3, 45.7, 39.7, 34.9; IR (KBr) ν: 3059, 2912, 2852, 1895, 1816, 1698, 1628, 1591, 1486, 1409, 1249, 1187, 1091, 1014, 949, 892, 817, 765, 710 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H33Cl3NO4 ([M + H]+), 792.1475; found, 792.1501.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Bromobenzyl)-2′,5′-bis(4-chlorophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4f)

The product is obtained as a yellow solid, 82%, 0.685 g, mp 169–171 °C; 1H NMR (400 MHz, CDCl3): δ 7.52–7.35 (m, 10H), 7.18–7.09 (m, 6H), 7.09 (s, 1H), 6.96–6.86 (m, 8H), 5.28 (s, 1H), 4.92 (s, 1H), 3.96 (d, J = 14.2 Hz, 1H), 3.76 (d, J = 13.7 Hz, 1H), 3.65–3.58 (m, 2H), 3.51 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.2, 200.9, 192.3, 174.5, 142.8, 141.4, 141.0, 137.4, 135.8, 135.5, 135.2, 134.1, 134.0, 133.3, 132.7, 132.1, 131.9, 131.7, 130.4, 130.2, 128.8, 128.7, 128.6, 128.6, 128.0, 126.3, 122.4, 122.1, 121.4, 121.3, 118.3, 106.2, 89.8, 64.1, 63.1, 52.4, 45.7, 39.7, 34.9; IR (KBr) ν: 3054, 2911, 2849, 1896, 1698, 1591, 1483, 1405, 1250, 1186, 1088, 1012, 951, 891, 819, 763, 712 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H33BrCl2NO4 ([M + H]+), 836.0970; found, 836.0982.

(2′S,4′R,4a′S,5′S,11a′S)-1′-Benzyl-2′,4′,5′-tris(4-chlorophenyl)-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4g)

The product is obtained as a yellow solid, 76%, 0.602 g, mp 164–166 °C; 1H NMR (400 MHz, CDCl3): δ 7.53–7.36 (m, 8H), 7.28 (s, 5H), 7.12–7.10 (m, 5H), 6.96 (d, J = 8.1 Hz, 4H), 6.84 (t, J = 8.0 Hz, 3H), 5.35 (s, 1H), 4.90 (s, 1H), 3.95 (d, J = 13.6 Hz, 1H), 3.83 (d, J = 13.6 Hz, 1H), 3.61 (s, 2H), 3.42 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.0, 200.8, 192.3, 174.6, 142.7, 141.2, 141.0, 137.4, 136.4, 135.7, 135.5, 134.1, 134.1, 133.8, 133.4, 133.2, 132.6, 132.1, 130.4, 129.1, 129.0, 128.8, 128.7, 128.6, 128.6, 127.8, 127.5, 122.5, 122.2, 121.3, 118.4, 106.0, 89.6, 64.3, 63.1, 52.8, 44.8, 39.5, 34.9; IR (KBr) ν: 3064, 2958, 2850, 1910, 1820, 1698, 1593, 1484, 1411, 1360, 1252, 1195, 1092, 1014, 955, 886, 827, 754, 703, 634 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H33Cl3NO4 ([M + H]+), 792.1475; found, 792.1480.

(2′S,4′R,4a′S,5′S,11a′S)-1′-Benzyl-2′,5′-bis(4-chlorophenyl)-4′-(4-methoxyphenyl)-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4h)

The product is obtained as a yellow solid, 73%, 0.575 g, mp 131–133 °C; 1H NMR (400 MHz, CDCl3): δ 7.54–7.41 (m, 6H), 7.37–7.28 (m, 7H), 7.23 (s, 1H), 7.11–7.05 (m, 3H), 6.95 (s, 3H), 6.87 (d, J = 8.0 Hz, 2H), 6.79 (d, J = 8.0 Hz, 1H), 6.63 (d, J = 9.0 Hz, 1H), 6.48 (d, J = 8.3 Hz, 1H), 5.35 (s, 1H), 4.90 (s, 1H), 3.96 (d, J = 13.5 Hz, 1H), 3.82 (d, J = 13.6 Hz, 1H), 3.59 (m, 5H), 3.50 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.4, 201.2, 192.4, 174.7, 158.9, 142.9, 141.5, 141.1, 137.6, 136.6, 135.4, 135.2, 134.4, 133.9, 133.4, 133.0, 132.4, 132.1, 130.3, 128.7, 128.6, 128.6, 128.5, 127.4, 127.3, 122.4, 122.0, 121.2, 118.3, 114.6, 113.5, 106.2, 89.8, 64.2, 63.3, 55.1, 52.8, 44.8, 39.8, 34.7; IR (KBr) ν: 3033, 2943, 2839, 1898, 1699, 1594, 1502, 1407, 1254, 1182, 1093, 1022, 952, 889, 824, 755, 708 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C49H36Cl2NO4 ([M + H]+), 788.1971; found, 788.1978.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(3-fluorophenyl)-1′-(4-methylbenzyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4i)

The product is obtained as a yellow solid, 67%, 0.496 g, mp 155–157 °C; 1H NMR (400 MHz, CDCl3): δ 7.49–7.34 (m, 8H), 7.18 (t, J = 8.4 Hz, 3H), 7.13–7.07 (m, 5H), 6.96 (s, 3H), 6.83–6.73 (m, 4H), 6.62 (t, J = 10.6 Hz, 2H), 5.35 (s, 1H), 4.93 (s, 1H), 3.87 (q, J = 13.4, 12.7 Hz, 2H), 3.67–3.60 (m, 2H), 3.51 (s, 1H), 2.32 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 201.0, 192.4, 174.8, 164.0, 161.6, 145.6, 142.8, 141.1, 137.5, 137.2, 135.3, 135.0, 133.5, 132.1, 131.9, 130.3, 130.0, 129.9, 129.2, 128.7, 128.5, 127.9, 126.5, 123.0, 122.0, 121.2, 118.4, 114.4, 114.2, 113.7, 113.5, 106.0, 89.6, 63.2, 52.7, 45.5, 39.4, 35.2, 21.0; IR (KBr) ν: 3037, 2960, 2918, 2854, 1894, 1738, 1698, 1592, 1463, 1415, 1247, 1189, 1146, 1074, 1025, 938, 880, 764, 702, 632 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C49H36F2NO4 ([M + H]+), 740.2612; found, 740.2620.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(3-fluorophenyl)-1′-(4-methoxybenzyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4j)

The product is obtained as a yellow solid, 64%, 0.484 g, mp 129–131 °C; 1H NMR (400 MHz, CDCl3): δ 7.49–7.38 (m, 8H), 7.24–7.08 (m, 6H), 6.96 (s, 3H), 6.87–6.74 (m, 6H), 6.62 (d, J = 6.0 Hz, 2H), 5.36 (s, 1H), 4.90 (d, J = 14.9 Hz, 1H), 3.90–3.79 (m, 5H), 3.66–3.60 (m, 2H), 3.52 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.0, 192.4, 174.8, 164.0, 161.6, 159.0, 145.6, 145.6, 142.8, 141.1, 137.5, 135.3, 135.0, 133.5, 132.1, 131.9, 130.3, 130.1, 130.0, 129.9, 128.7, 128.6, 127.9, 126.5, 123.0, 123.0, 122.3, 122.0, 121.3, 118.4, 114.4, 114.2, 114.0, 113.7, 113.5, 106.0, 89.6, 63.2, 55.3, 52.4, 45.5, 39.4, 35.2; IR (KBr) ν: 3042, 2947, 2844, 1956, 1882, 1701, 1595, 1502, 1455, 1388, 1249, 1168, 1076, 1024, 941, 878, 761, 701, 638 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C49H36F2NO5 ([M + H]+), 756.2562; found, 756.2566.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Chlorobenzyl)-2′,5′-bis(3-fluorophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4k)

The product is obtained as a yellow solid, 63%, 0.479 g, mp 163–165 °C; 1H NMR (400 MHz, CDCl3): δ 7.53–7.35 (m, 10H), 7.19–7.10 (m, 4H), 7.97–6.86 (m, 6H), 6.75–7.61 (m, 5H), 5.31 (s, 1H), 4.93 (s, 1H), 3.99 (d, J = 13.7 Hz, 1H), 3.82 (d, J = 13.2 Hz, 1H), 3.69 (d, J = 12.8 Hz, 1H), 3.61 (d, J = 13.2 Hz, 1H), 3.53 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.1, 200.8, 192.3, 174.6, 164.1, 161.7, 145.5, 145.4, 142.8, 141.0, 138.1, 138.1, 137.4, 135.4, 135.2, 135.1, 133.4, 133.2, 132.2, 131.9, 130.4, 130.1, 130.0, 129.9, 128.8, 128.7, 128.6, 128.0, 126.4, 122.9, 122.8, 122.4, 122.1, 121.4, 118.4, 114.5, 114.2, 113.9, 113.7, 106.0, 89.7, 63.1, 52.3, 45.5, 39.5, 35.2; IR (KBr) ν: 3058, 2947, 2909, 2863, 1959, 1695, 1590, 1482, 1376, 1268, 1178, 1078, 1012, 933, 879, 752, 700 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H33ClF2NO ([M + H]+), 760.2066; found, 760.2069.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Bromobenzyl)-2′,5′-bis(3-fluorophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4l)

The product is obtained as a yellow solid, 73%, 0.587 g, mp 170–172 °C; 1H NMR (400 MHz, CDCl3): δ 7.53–7.39 (m, 10H), 7.20–7.11 (m, 5H), 7.97–6.86 (m, 6H), 6.75–6.61 (m, 4H), 5.31 (s, 1H), 4.94 (s, 1H), 3.98 (d, J = 14.1 Hz, 1H), 3.81 (d, J = 14.3 Hz, 1H), 3.71–3.60 (m, 2H), 3.53 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.0, 200.8, 192.3, 174.6, 164.1, 161.7, 145.5, 145.4, 142.8, 141.0, 138.1, 138.0, 137.4, 135.4, 135.2, 135.1, 133.4, 132.1, 131.9, 131.7, 130.4, 130.3, 130.1, 130.0, 128.8, 128.6, 128.0, 126.4, 122.8, 122.8, 122.4, 122.0, 121.4, 118.3, 114.5, 114.3, 113.9, 113.7, 106.1, 89.7, 63.1, 52.4, 45.5, 39.5, 35.1; IR (KBr) ν: 3056, 2946, 2908, 2862, 1960, 1736, 1696, 1591, 1482, 1378, 1248, 1180, 1072, 1006, 933, 880, 761, 701, 639 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H33BrF2N5O6 ([M + H]+), 804.1561; found, 804.1556.

(2′S,4′R,4a′S,5′S,11a′S)-1′-Benzyl-2′,5′-bis(4-bromophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4m)

The product is obtained as a yellow solid, 78%, 0.661 g, mp 137–139 °C; 1H NMR (400 MHz, CDCl3): δ 7.52–7.41 (m, 7H), 7.36 (t, J = 6.6 Hz, 2H), 7.33–7.28 (m, 5H), 7.24 (s, 2H), 7.15–7.05 (m, 5H), 6.96–6.94 (m, 2H), 6.86–6.81 (m, 3H), 5.36 (s, 1H), 4.91 (s, 1H), 3.97 (d, J = 13.7 Hz, 1H), 3.83 (d, J = 13.7 Hz, 1H), 3.62 (s, 2H), 3.48 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 201.1, 201.0, 192.4, 174.7, 142.8, 142.0, 141.1, 137.5, 136.5, 135.4, 135.3, 135.2, 134.9, 133.4, 132.1, 131.9, 131.6, 130.3, 129.1, 128.8, 128.6, 128.5, 127.9, 127.5, 126.4, 122.4, 122.2, 122.1, 121.3, 120.6, 118.4, 106.1, 89.8, 64.2, 63.2, 52.9, 45.7, 39.5, 35.0; IR (KBr) ν: 3032, 2868, 1893, 1826, 1700, 1637, 1595, 1483, 1414, 1371, 1249, 1184, 1074, 1012, 948, 892, 818, 765, 703, 654 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C48H34Br2NO4 ([M + H]+), 848.0834; found, 848.0844.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Methylbenzyl)-4′-phenyl-2′,5′-di-p-tolyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4n)

The product is obtained as a yellow solid, 60%, 0.439 g, mp 150–152 °C; 1H NMR (400 MHz, CDCl3): δ 7.49–7.44 (m, 2H), 7.40–7.31 (m, 6H), 7.19 (t, J = 6.9 Hz, 3H), 7.11–7.00 (m, 4H), 6.92 (d, J = 5.6 Hz, 4H), 6.86–6.81 (m, 4H), 6.77 (s, 2H), 5.41 (s, 1H), 4.89 (s, 1H), 3.91–3.82 (m, 2H), 3.68–3.59 (m, 2H), 3.49 (s, 1H), 2.32 (s, 3H), 2.26 (s, 3H), 2.03 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 201.5, 201.3, 192.7, 174.6, 143.0, 141.2, 140.0, 137.9, 137.7, 136.6, 135.9, 135.8, 134.9, 134.6, 134.5, 134.0, 133.7, 132.7, 131.9, 131.9, 130.0, 129.1, 129.0, 128.8, 128.5, 128.4, 127.8, 127.6, 127.2, 126.7, 122.2, 121.9, 121.0, 118.2, 106.9, 90.2, 64.5, 63.6, 52.4, 45.7, 39.4, 35.1, 21.1, 21.0, 20.9; IR (KBr) ν: 3029, 2918, 2862, 1956, 1699, 1646, 1591, 1487, 1372, 1245, 1172, 1092, 1013, 952, 893, 815, 758, 706, 612 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C51H42NO4 ([M + H]+), 732.3114; found, 732.3142.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Chlorobenzyl)-4′-phenyl-2′,5′-di-p-tolyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4o)

The product is obtained as a yellow solid, 65%, 0.489 g, mp 145–147 °C; 1H NMR (400 MHz, CDCl3): δ 7.50–7.31 (m, 8H), 7.26–7.14 (m, 6H), 7.08–7.05 (m, 1H), 6.98–6.93 (m, 4H), 6.84 (d, J = 7.8 Hz, 4H), 6.76 (d, J = 7.7 Hz, 2H), 5.35 (s, 1H), 4.90 (s, 1H), 3.95 (d, J = 14.4 Hz, 1H), 3.84 (d, J = 13.7 Hz, 1H), 3.64 (q, J = 13.2 Hz, 2H), 3.51 (s, 1H), 2.29 (s, 3H), 2.03 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 201.4, 201.3, 192.6, 174.5, 143.0, 141.2, 139.9, 137.9, 137.7, 136.2, 135.9, 135.7, 135.0, 134.7, 133.6, 132.8, 132.4, 131.9, 131.9, 130.1, 130.0, 129.2, 128.7, 128.6, 128.5, 128.4, 127.7, 127.1, 126.6, 122.2, 121.9, 121.1, 118.2, 106.9, 90.1, 64.4, 63.4, 52.0, 45.7, 39.6, 35.0, 21.0, 20.9; IR (KBr) ν: 3027, 2915, 2861, 1952, 1888, 1699, 1637, 1593, 1481, 1412, 1370, 1244, 1175, 1090, 1015, 939, 857, 761, 703 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C50H39NO4 ([M + H]+), 752.2568; found, 752.2504.

(2′S,4′R,4a′S,5′S,11a′S)-1′-(4-Chlorobenzyl)-4′-phenyl-2′,5′-di-m-tolyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4p)

The product is obtained as a yellow solid, 60%, 0.451 g, mp 140–142 °C; 1H NMR (400 MHz, CDCl3): δ 7.48 (t, J = 5.9 Hz, 2H), 7.43–7.35 (m, 6H), 7.26–7.19 (m, 4H), 7.09–7.02 (m, 4H), 6.96 (d, J = 4.0 Hz, 3H), 6.88–6.77 (m, 5H), 6.70 (d, J = 5.9 Hz, 1H), 6.65 (s, 1H), 5.40 (s, 1H), 4.87 (s, 1H), 3.90 (q, J = 15.2, 14.4 Hz, 2H), 3.67–3.60 (m, 2H), 3.50 (s, 1H), 2.18 (s, 3H), 2.06 (d, J = 13.3 Hz, 3H); 13C NMR (100 MHz, CDCl3): δ 201.3, 201.2, 192.5, 174.4, 142.9, 138.1, 137.8, 135.7, 135.7, 135.0, 134.7, 133.6, 133.0, 132.0, 132.0, 130.2, 130.1, 128.6, 128.6, 128.5, 128.4, 127.7, 127.6, 127.5, 126.7, 124.6, 121.2, 118.2, 106.8, 89.8, 64.9, 63.4, 52.2, 45.5, 39.4, 35.3, 21.4; IR (KBr) ν: 3066, 2940, 2855, 1949, 1872, 1740, 1702, 1636, 1593, 1486, 1417, 1368, 1247, 1196, 1145, 1073, 1010, 960, 876, 762, 701, 638 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C50H39ClNO4 ([M + H]+), 752.2568; found, 752.2588.

(2′S,4′R,4a′S,5′S,11a′S)-1′-Butyl-2′,5′-bis(3-fluorophenyl)-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4q)

The product is obtained as a yellow solid, 76%, 0.526 g, mp 151–153 °C; 1H NMR (400 MHz, CDCl3): δ 7.52–7.28 (m, 10H), 7.22 (d, J = 8.3 Hz, 1H), 7.11 (s, 1H), 7.03–6.87 (m, 7H), 6.75–6.68 (m, 1H), 6.62 (t, J = 8.6 Hz, 1H), 5.64 (s, 1H), 4.84 (d, J = 17.9 Hz, 1H), 3.80 (d, J = 13.9 Hz, 1H), 3.61–3.57 (m, 2H), 3.04–2.93 (m, 1H), 2.58 (br s, 1H), 1.50 (s, 1H), 1.30 (s, 1H), 1.15–1.07 (m, 2H), 0.76 (t, J = 7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3): δ 201.2, 201.0, 192.5, 175.3, 164.3, 161.8, 145.9, 145.8, 142.8, 141.0, 137.5, 135.4, 135.3, 134.9, 133.5, 132.1, 32.0, 130.3, 130.2, 129.6, 128.8, 128.6, 127.9, 126.5, 123.4, 123.3, 122.3, 122.0, 121.2, 118.5, 114.8, 114.6, 113.9, 113.7, 105.5, 92.0, 63.0, 50.1, 45.4, 40.0, 35.2, 29.1, 20.3, 13.8; IR (KBr) ν: 3068, 2960, 2864, 1956, 1880, 1738, 1698, 1589, 1459, 1411, 1376, 1249, 1196, 1148, 1071, 1014, 936, 877, 768, 704, 630 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C45H36F2NO4 ([M + H]+), 692.2612; found, 692.2608.

(2′S,4′R,4a′S,5′S,11a′S)-2′,5′-Bis(4-bromophenyl)-1′-butyl-4′-phenyl-1′,4a′,5′,11a′-tetrahydro-2′H-spiro[indene-2,3′-indeno[2′,1′:5,6]pyrano[2,3-b]pyridine]-1,3,6′(4′H)-trione (4r)

The product is obtained as a yellow solid, 62%, 0.505 g, mp 134–136 °C; 1H NMR (400 MHz, CDCl3): δ 7.51–7.36 (m, 10H), 7.19–7.09 (m, 7H), 6.95 (s, 2H), 6.85 (s, 2H), 5.60 (s, 1H), 4.81 (s, 1H), 3.72 (d, J = 13.0 Hz, 1H), 3.58–3.56 (m, 2H), 2.97–2.90 (m, 1H), 2.54 (br s, 1H), 1.47 (br s, 2H), 1.14–1.06 (m, 2H), 0.77 (t, J = 6.5 Hz, 3H3); 13C NMR (100 MHz, CDCl3): δ 201.3, 201.1, 192.6, 175.3, 142.7, 142.2, 141.0, 137.5, 135.4, 135.3, 135.1, 134.7, 133.5, 132.1, 132.1, 131.9, 131.8, 131.3, 131.0, 130.3, 130.0, 129.4, 128.8, 128.5, 127.9, 126.4, 123.5, 122.3, 122.1, 121.9, 121.3, 120.8, 118.5, 105.6, 91.9, 63.5, 63.0, 50.1, 45.5, 40.0, 34.9, 29.1, 20.3, 18.4, 13.9.; IR (KBr) ν: 3064, 2951, 2862, 1895, 1700, 1632, 1591, 1478, 1411, 1369, 1250, 1195, 1072, 1009, 955, 888, 816, 761, 706 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C45H38BrNO4 ([M + H]+), 814.0991; found, 814.1009.

General Procedure for the Synthesis of Dispiro Compounds 5a–5m

A mixture of α,β-unsaturated N-arylaldimine (0.5 mmol) and 2,2′-(arylmethylene)bis(indene-1,3-dione) (0.5 mmol) in dry acetonitrile (10.0 mL) was stirred at room temperature for 10 h. The solvent was removed by rotatory evaporation at reduced pressure. The residue was subjected with silicon column chromatography with mixed petroleum ether and ethyl acetate (v/v = 2:1) as an eluant to give a pure product for analysis.

2′,4′-Diphenyl-6′-(phenylamino)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5a)

The product is obtained as a yellow solid, 86%, 0.253 g, mp 179–183 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.11 (d, J = 7.3 Hz, 1H), 7.73 (m, J = 7.2 Hz, 1H), 7.65–7.34 (m, 6H), 7.13–6.86 (m, 7H), 6.79–6.56 (m, 7H), 6.55–6.42 (m, 1H), 4.99–4.94 (m, 2H), 4.31–4.27 (m, 1H), 4.07 (d, J = 12.1 Hz, 1H), 3.47–3.39 (m, 1H), 2.04 (d, J = 13.5 Hz, 1H); cis-isomer: 7.96 (d, J = 7.3 Hz, 1H), 7.65–7.34 (m, 7H), 4.70 (s, 1H), 4.65 (d, J = 11.9 Hz, 1H), 4.20 (d, J = 12.5 Hz, 1H), 3.05 (d, J = 11.5 Hz, 1H), 2.34 (d, J = 13.4 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 203.4, 203.1, 202.7, 202.6, 202.2, 201.5, 201.3, 201.1, 146.1, 144.0, 143.1, 142.8, 142.6, 142.3, 141.6, 141.4, 139.1, 139.0, 135.6, 135.3, 135.1, 135.0, 134.9, 134.8, 134.0, 133.6, 130.9, 129.1, 129.0, 128.7, 128.6, 128.4, 128.0, 128.0, 127.8, 127.6, 127.4, 127.3, 127.0, 126.9, 122.9, 122.7, 122.5, 122.4, 122.3, 122.2, 115.4, 115.2, 114.7, 63.7, 63.3, 62.6, 61.9, 58.1, 56.1, 55.4, 53.7, 53.0, 51.9, 45.6, 43.6, 31.3, 31.2; IR (KBr) ν: 3039, 1704, 1595, 1499, 1446, 1341, 1248, 1155, 1115, 1031, 958, 884, 760 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C40H30NO4 ([M + H]+), 588.2175; found, 588.2177.

4′-Phenyl-6′-(phenylamino)-2′-(p-tolyl)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5b)

The product is obtained as a yellow solid, 89%, 0.268 g, mp 184–189 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.10 (d, J = 8.4 Hz, 1H), 7.73 (t, J = 7.0 Hz, 1H), 7.64–7.36 (m, 6H), 7.08–6.88 (m, 7H), 6.66–6.45 (m, 7H), 4.95 (d, J = 16.0 Hz, 2H), 4.27 (d, J = 8.8 Hz, 1H), 4.06 (d, J = 12.8 Hz, 1H), 3.45–3.36 (m, 1H), 2.01 (d, J = 14.0 Hz, 1H), 1.98–1.80 (m, 3H); cis-isomer: 7.96 (d, J = 7.6 Hz, 1H), 7.64–7.36 (m, 7H), 4.67–4.63 (m, 2H), 4.19 (d, J = 11.2 Hz, 1H), 3.09–2.98 (m, 1H), 2.33 (d, J = 9.6 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 203.5, 203.2, 202.8, 202.7, 202.2, 201.5, 201.2, 146.1, 144.0, 143.1, 142.8, 142.6, 142.4, 141.6, 141.4, 139.1, 139.1, 136.8, 135.5, 135.2, 135.0, 134.9, 134.8, 134.7, 131.0, 130.8, 130.5, 130.2, 129.1, 129.0, 128.6, 128.5, 128.3, 127.9, 127.9, 127.0, 126.9, 122.9, 122.8, 122.7, 122.4, 122.3, 122.2, 118.8, 118.4, 115.4, 115.2, 114.6, 110.0, 63.8, 63.4, 62.7, 61.9, 56.1, 53.7, 52.5, 51.4, 45.6, 43.7, 31.3, 31.2, 20.7, 20.6; IR (KBr) ν: 3026, 1704, 1596, 1499, 1347, 1248, 1153, 1032, 959, 882, 754 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C41H32NO4 ([M + H]+), 602.2331; found, 602.2330.

2′-(2-Fluorophenyl)-4′-phenyl-6′-(phenylamino)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5c)

The product is obtained as a yellow solid, 92%, 0.289 g, mp 166–169 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.11 (d, J = 8.0 Hz, 1H), 7.74 (t, J = 8.0 Hz, 1H), 7.67–7.43 (m, 6H), 7.11–6.96 (m, 8H), 6.79–6.36 (m, 7H), 5.07–4.96 (m, 2H), 4.86 (s, 1H), 3.92 (d, J = 16.0 Hz, 1H), 3.57–3.48 (m, 1H), 2.01 (d, J = 16.0 Hz, 1H); cis-isomer: 7.97 (d, J = 8.0 Hz, 1H), 7.67–7.43 (m, 7H), 6.79–6.36 (m, 8H), 5.26 (s, 1H), 4.66 (t, J = 12.6 Hz, 1H), 4.36 (d, J = 12.8 Hz, 1H), 4.26 (d, J = 12.8 Hz, 1H), 3.20–3.11 (m, 1H), 2.38 (d, J = 16.8 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 202.2, 202.2, 202.1, 202.1, 202.1, 201.6, 201.4, 158.4, 146.0, 143.9, 142.5, 142.3, 141.3, 138.9, 135.6, 135.1, 135.0, 132.3, 129.1, 129.0, 128.8, 128.6, 128.0, 128.0, 127.0, 122.9, 122.8, 122.5, 122.3, 119.0, 115.5, 115.2, 114.7, 62.7, 62.5, 56.0, 54.2, 45.4, 43.6, 42.4, 31.6, 31.4; IR (KBr) ν: 3049, 2093, 1705, 1595, 1496, 1447, 1342, 1247, 1102, 957, 885, 760 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C40H28FNNaO4 ([M + Na]+), 628.1900; found, 628.1902.

4′-((3-Chlorophenyl)amino)-2′-(2-fluorophenyl)-6′-phenyldispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5d)

The product is obtained as a yellow solid, 90%, 0.298 g, mp 186–187 °C; 1H NMR (600 MHz, CDCl3): δ trans-isomer: 8.11 (d, J = 7.5 Hz, 1H), 7.76 (t, J = 7.1 Hz, 1H), 7.62–7.52 (m, 3H), 7.49–7.43 (m, 3H), 7.11–7.07 (m, 2H), 7.04–6.91 (m, 4H), 6.86–6.69 (m, 2H), 6.59–6.54 (m, 3H), 6.47–6.33 (m, 2H), 5.03 (d, J = 13.7 Hz, 1H), 4.95 (t, J = 18.6 Hz, 1H), 4.85 (s, 1H), 4.03 (d, J = 11.9 Hz, 1H), 3.57–3.51 (m, 1H), 1.99 (d, J = 15.2 Hz, 1H); cis-isomer: 8.00 (d, J = 7.1 Hz, 1H), 7.68 (t, J = 7.7 Hz, 1H), 7.49–7.43 (m, 4H), 6.86–6.69 (m, 3H), 6.47–6.33 (m, 4H), 5.24 (s, 1H), 4.61 (br s, 1H), 4.38 (d, J = 12.3 Hz, 2H), 3.19–3.13 (m, 1H), 2.36 (d, J = 16.2 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 202.1, 201.9, 201.5, 201.3, 160.9, 158.4, 147.2, 143.8, 142.4, 142.2, 141.3, 138.7, 135.8, 135.6, 135.3, 135.2, 135.0, 134.8, 134.7, 132.3, 130.1, 130.0, 129.3, 129.2, 128.7, 128.6, 128.0, 127.1, 123.1, 123.0, 122.8, 122.5, 122.3, 118.8, 118.2, 115.5, 115.3, 114.9, 114.2, 113.2, 112.7, 62.6, 62.4, 62.3, 55.5, 53.7, 53.4, 45.1, 43.6, 42.4, 31.5, 31.3; IR (KBr) ν: 3063, 1706, 1591, 1486, 1343, 1246, 1088, 991, 958, 882, 763 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C40H27ClFNNaO4 ([M + Na]+), 662.1510; found, 662.1503.

2′-(2-Chlorophenyl)-4′-phenyl-6′-(phenylamino)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5e)

The product is obtained as a yellow solid, 88%, 0.273 g, mp 162–164 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.10 (d, J = 6.8 Hz, 1H), 7.73 (t, J = 6.8 Hz, 1H), 7.62 (d, J = 8.0 Hz, 1H), 7.57–7.43 (m, 5H), 7.15–6.83 (m, 9H), 6.69–6.47 (m, 5H), 5.15–5.01 (m, 3H), 3.80 (d, J = 12.0 Hz, 1H), 3.60–3.51 (m, 1H), 2.02 (d, J = 13.6 Hz, 1H); cis-isomer: 7.92 (d, J = 6.8 Hz, 1H), 7.62 (d, J = 8.0 Hz, 2H), 5.43 (s, 1H), 4.73 (t, J = 11.4 Hz, 1H), 4.37 (d, J = 12.4 Hz, 1H), 4.26 (d, J = 11.6 Hz, 1H), 3.28–3.18 (m, 1H), 2.40 (d, J = 13.6 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 202.3, 202.0, 201.6, 201.1, 149.8, 146.1, 144.0, 142.5, 142.4, 141.5, 138.9, 135.5, 135.3, 135.1, 135.0, 134.7, 132.7, 131.7, 131.6, 130.0, 129.7, 129.1, 129.1, 129.0, 128.8, 128.5, 128.4, 127.9, 127.0, 125.9, 125.5, 122.9, 122.6, 122.5, 122.3, 119.0, 118.5, 115.2, 114.7, 63.2, 62.3, 62.2, 62.0, 55.8, 54.6, 47.3, 45.6, 45.1, 43.6, 32.1, 31.4, 15.0; IR (KBr) ν: 3058, 1739, 1704, 1597, 1501, 1325, 1247, 1041, 761 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C40H29ClNO4 ([M + H]+), 622.1785; found, 622.1788.

2′-(2-Chlorophenyl)-4′-((3-chlorophenyl)amino)-6′-phenyldispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5f)

The product is obtained as a yellow solid, 91%, 0.298 g, mp 166–170 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.10 (d, J = 9.2 Hz, 1H), 7.75 (t, J = 6.4 Hz, 1H), 7.68–7.42 (m, 6H), 7.15–6.81 (m, 8H), 6.69–6.52 (m, 2H), 6.47 (d, J = 8.0 Hz, 1H), 6.37 (t, J = 9.4 Hz, 2H), 5.12–5.08 (m, 2H), 4.99 (t, J = 10.4 Hz, 1H), 3.90 (d, J = 11.2 Hz, 1H), 3.62–3.52 (m, 1H), 2.00 (d, J = 15.2 Hz, 1H); cis-isomer: 7.96 (d, J = 8.4 Hz, 1H), 7.68–7.42 (m, 7H), 6.69–6.52 (m, 3H), 5.41 (s, 1H), 4.70–4.64 (m, 1H), 4.42–4.38 (m, 2H), 3.28–3.18 (m, 1H), 2.40–2.36 (m, 1H); 13C NMR (100 MHz, CDCl3): δ 203.0, 202.1, 201.8, 201.3, 201.1, 201.0, 199.8, 147.3, 147.3, 143.9, 142.8, 142.7, 142.5, 142.3, 142.2, 141.5, 138.8, 138.7, 135.6, 135.3, 135.1, 134.8, 134.8, 134.6, 132.7, 132.1, 131.6, 131.5, 130.1, 130.0, 129.8, 129.0, 128.8, 128.5, 128.0, 127.1, 125.9, 123.0, 122.9, 122.5, 118.3, 115.0, 114.3, 114.2, 112.7, 63.1, 62.2, 62.0, 61.9, 55.4, 47.3, 47.2, 45.6, 45.5, 44.9, 31.4; IR (KBr) ν: 33 064, 1739, 1704, 1593, 1480, 1327, 1246, 1159, 1084, 1039, 989, 852, 764 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C40H28Cl2NO4 ([M + H]+), 656.1395; found, 656.1390.

2′-(2-Chlorophenyl)-4′-((4-methoxyphenyl)amino)-6′-phenyldispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5g)

The product is obtained as a yellow solid, 88%, 0.287 g, mp 158–160 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.08 (d, J = 7.4 Hz, 1H), 7.72 (t, J = 7.3 Hz, 1H), 7.61 (d, J = 7.7 Hz, 1H), 7.57–7.41 (m, 5H), 7.15–7.09 (m, 2H), 7.02–6.83 (m, 5H), 6.68–6.43 (m, 6H), 5.14 (d, J = 12.3 Hz, 1H), 5.06 (s, 1H), 4.94–4.89 (m, 1H), 3.65 (s, 3H), 3.56–3.47 (m, 2H), 2.02 (d, J = 14.9 Hz, 1H); cis-isomer: 7.89 (d, J = 6.8 Hz, 1H), 7.05 (d, J = 7.7 Hz, 1H), 5.41 (s, 1H), 4.32 (d, J = 10.9 Hz, 1H), 4.00 (d, J = 13.3 Hz, 1H), 3.68 (s, 1H), 3.60 (s, 3H), 3.26–3.16 (m, 1H), 2.39 (d, J = 12.9 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 202.3, 201.9, 201.7, 201.1, 153.1, 144.1, 142.4, 142.4, 141.5, 140.0, 138.9, 135.3, 135.0, 134.6, 132.7, 131.7, 129.7, 129.0, 128.8, 128.5, 127.9, 127.0, 125.4, 122.8, 122.7, 122.5, 122.3, 117.2, 117.1, 114.6, 114.5, 63.3, 62.3, 56.4, 56.2, 55.7, 55.5, 47.4, 47.2, 43.6, 43.4, 31.8; IR (KBr) ν: 3040, 1739, 1704, 1593, 1513, 1447, 1329, 1248, 1177, 1130, 1032, 825, 766 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C41H30ClNNaO5 ([M + Na]+), 674.1710; found, 674.1705.

2′-(4-Bromophenyl)-4′-phenyl-6′-(phenylamino)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5h)

The product is obtained as a yellow solid, 87%, 0.290 g, mp 180–182 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.09 (d, J = 7.6 Hz, 1H), 7.75 (t, J = 7.6 Hz, 1H), 7.68–7.35 (m, 6H), 7.05–6.80 (m, 9H), 6.68–6.41 (m, 5H), 4.92 (d, J = 12.4 Hz, 2H), 4.28–4.23 (m, 1H), 4.00 (d, J = 11.6 Hz, 1H), 3.41–3.32 (m, 1H), 2.00 (d, J = 14.0 Hz, 1H); cis-isomer: 7.96 (d, J = 7.6 Hz, 1H), 7.68–7.35 (m, 7H), 6.68–6.41 (m, 6H), 4.68 (d, J = 1.6 Hz, 1H), 4.60 (s, 1H), 3.45–3.36 (m, 1H), 4.15 (d, J = 11.6 Hz, 1H), 3.04–2.94 (m, 1H), 2.32 (d, J = 13.6 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 203.2, 202.8, 202.6, 202.4, 201.9, 201.3, 201.1, 200.8, 146.0, 145.9, 143.8, 142.8, 142.4, 142.3, 142.3, 141.5, 141.4, 138.8, 138.7, 135.8, 135.5, 135.3, 135.3, 135.1, 133.4, 132.9, 132.5, 131.0, 130.8, 129.1, 129.0, 128.5, 128.4, 128.0, 128.0, 127.1, 127.1, 123.0, 122.9, 122.6, 122.5, 122.4, 122.3, 121.6, 119.0, 118.6, 115.3, 114.7, 63.6, 63.2, 62.4, 61.7, 56.2, 53.9, 51.8, 50.6, 45.9, 43.9, 31.3, 31.2; IR (KBr) ν: 3053, 1737, 1701, 1595, 1494, 1332, 1248, 1078, 1006, 959, 762 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C40H29BrNO4 ([M + H]+), 666.1280; found, 666.1274.

2′-(2-Bromophenyl)-4′-phenyl-6′-(phenylamino)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5i)

The product is obtained as a yellow solid, 90%, 0.300 g, mp 163–164 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.09 (d, J = 3.6 Hz, 1H), 7.73 (t, J = 7.0 Hz, 1H), 7.66–7.42 (m, 6H), 7.16–6.90 (m, 9H), 6.68–6.49 (m, 5H), 5.14 (d, J = 10.0 Hz, 1H), 5.08–5.03 (m, 2H), 3.74 (d, J = 12.8 Hz, 1H), 3.55–3.51 (m, 1H), 2.03 (d, J = 14.8 Hz, 1H); cis-isomer: 7.90 (d, J = 8.4 Hz, 1H), 7.66–7.42 (m, 7H), 5.37 (s, 1H), 4.79–4.74 (m, 1H), 4.37 (d, J = 7.6 Hz, 1H), 4.25 (d, J = 10.8 Hz, 1H), 3.30–3.19 (m, 1H), 2.42 (d, J = 12.8 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 203.1, 202.3, 202.1, 202.0, 201.3, 201.0, 200.7, 199.9, 146.1, 144.1, 143.0, 142.7, 142.4, 142.3, 141.6, 139.0, 138.9, 135.5, 135.3, 135.2, 135.1, 135.0, 134.0, 133.6, 133.5, 133.2, 132.8, 131.7, 129.2, 129.1, 129.0, 128.9, 128.7, 128.6, 128.0, 127.9, 127.0, 126.5, 126.1, 125.9, 125.7, 122.9, 122.9, 122.6, 122.5, 122.3, 119.0, 118.5, 115.5, 115.2, 114.7, 63.5, 62.1, 62.1, 55.8, 54.7, 50.2, 48.3, 45.1, 43.6, 32.3, 31.4; IR (KBr) ν: 3056, 1737, 1703, 1595, 1501, 1320, 1246, 1025, 760 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C40H29BrNO4 ([M + H]+), 666.1280; found, 666.1272.

2′-(2-Bromophenyl)-4′-phenyl-6′-(p-tolylamino)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5j)

The product is obtained as a yellow solid, 92%, 0.313 g, mp 160–161 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.08 (d, J = 8.1 Hz, 1H), 7.72 (t, J = 8.1 Hz, 1H), 7.66–7.61 (m, 1H), 7.57–7.41 (m, 5H), 7.15–6.84 (m, 9H), 6.61–6.52 (m, 4H), 5.14 (d, J = 13.2 Hz, 1H), 5.04–4.98 (m, 2H), 3.60 (d, J = 12.7 Hz, 1H), 3.55–3.47 (m, 1H), 2.13 (s, 3H), 2.05–2.00 (m, 1H); cis-isomer: 7.89 (d, J = 5.4 Hz, 1H), 7.66–7.61 (m, 2H), 6.73 (d, J = 8.0 Hz, 1H), 6.42 (d, J = 8.4 Hz, 1H), 5.36 (s, 1H), 4.72 (br s, 1H), 4.33 (d, J = 16.2 Hz, 1H), 4.10 (d, J = 11.1 Hz, 1H), 3.27–3.17 (m, 1H), 2.40 (d, J = 12.7 Hz, 1H), 2.07 (s, 1H); 13C NMR (100 MHz, CDCl3): δ 202.3, 202.1, 201.4, 201.0, 144.1, 143.8, 142.5, 142.5, 141.7, 139.0, 135.4, 135.1, 133.6, 133.2, 132.8, 129.6, 129.2, 128.9, 128.7, 128.4, 127.9, 127.0, 126.1, 125.8, 122.8, 122.6, 122.3, 115.6, 115.5, 63.5, 62.2, 55.4, 50.2, 50.1, 43.7, 32.1, 20.3; IR (KBr) ν: 2918, 1740, 1705, 1598, 1516, 1326, 1247, 1024, 817, 762, 700 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C41H31BrNO4 ([M + H]+), 680.1436; found, 680.1420.

2′-(2-Bromophenyl)-4′-((4-methoxyphenyl)amino)-6′-phenyldispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5k)

The product is obtained as a yellow solid, 90%, 0.313 g, mp 154–156 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.07 (d, J = 7.8 Hz, 1H), 7.72 (t, J = 7.3 Hz, 1H), 7.64 (d, J = 8.0 Hz, 1H), 7.57–7.41 (m, 5H), 7.16–6.91 (m, 7H), 6.62–6.45 (m, 6H), 5.15 (d, J = 13.3 Hz, 1H), 5.03 (s, 1H), 4.94 (t, J = 9.6 Hz, 1H), 3.66 (s, 3H), 3.53–3.46 (m, 2H), 2.03 (d, J = 12.9 Hz, 1H); cis-isomer: 7.87 (d, J = 8.6 Hz, 1H), 7.16–6.91 (m, 8H), 5.35 (s, 1H), 4.68 (br s, 1H), 4.31 (d, J = 11.9 Hz, 1H), 3.98 (d, J = 13.2 Hz, 1H), 3.60 (s, 3H), 3.27–3.18 (m, 1H), 2.39 (d, J = 12.8 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 202.3, 202.0, 201.5, 201.0, 153.2, 144.1, 142.5, 142.4, 141.7, 140.0, 139.0, 135.4, 135.1, 135.0, 133.5, 133.2, 132.8, 129.2, 128.9, 127.9, 127.0, 125.8, 122.8, 122.6, 117.2, 114.6, 63.6, 62.2, 56.4, 55.7, 43.6, 32.0; IR (KBr) ν: 3038, 1740, 1705, 1593, 1511, 1445, 1329, 1245, 1184, 1127, 1031, 829, 766 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C41H31BrNO5 ([M + H]+), 696.1386; found, 696.1373.

2′-(2-Bromophenyl)-4′-((4-methoxyphenyl)amino)-6′-(p-tolyl)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5l)

The product is obtained as a yellow solid, 93%, 0.330 g, mp 160–163 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.07 (d, J = 7.8 Hz, 1H), 7.73–7.61 (m, 2H), 7.56–7.42 (m, 5H), 7.07–7.00 (m, 4H), 6.85 (d, J = 6.9 Hz, 2H), 6.60–6.51 (m, 6H), 5.10 (d, J = 15.0 Hz, 1H), 5.01–4.96 (m, 2H), 3.60 (s, 3H), 3.57–3.44 (m, 2H), 2.13 (s, 3H), 1.99 (d, J = 15.3 Hz, 1H); cis-isomer: 7.88 (d, J = 7.6 Hz, 1H), 6.72 (d, J = 8.0 Hz, 2H), 6.41 (d, J = 6.6 Hz, 2H), 5.33 (s, 1H), 4.72 (br s, 1H), 4.28 (d, J = 12.9 Hz, 1H), 4.08 (d, J = 12.2 Hz, 1H), 3.06 (s, 3H), 3.23–3.14 (m, 1H), 2.36 (d, J = 13.6 Hz, 1H), 2.13 (s, 1H), 2.07 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 202.5, 202.1, 201.5, 201.2, 158.3, 144.1, 143.8, 142.6, 142.5, 141.7, 135.4, 135.1, 135.0, 133.6, 133.2, 132.7, 131.1, 130.2, 129.6, 128.4, 125.8, 122.8, 113.3, 63.5, 62.2, 55.0, 50.2, 32.5, 20.3; IR (KBr) ν: 2924, 1740, 1705, 1602, 1512, 1464, 1337, 1248, 1175, 1122, 1028, 835, 763, 726 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C42H33BrNO5 ([M + H]+), 710.1542; found, 710.1531.

2′-(2-Bromophenyl)-4′-(4-methoxyphenyl)-6′-((4-methoxyphenyl)amino)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5m)

The product is obtained as a yellow solid, 88%, 0.319 g, mp 137–142 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.06 (d, J = 7.4 Hz, 1H), 7.73–7.60 (m, 2H), 7.56–7.39 (m, 5H), 7.08–6.99 (m, 4H), 6.62–6.45 (m, 8H), 5.12–5.08 (m, 1H), 5.00 (s, 1H), 4.92 (t, J = 15.0 Hz, 1H), 3.66 (s, 3H), 3.61 (s, 3H), 3.52–3.43 (m, 2H), 1.99 (d, J = 13.1 Hz, 1H); cis-isomer: 7.86 (d, J = 6.6 Hz, 1H), 5.32 (s, 1H), 4.67 (br s, 1H), 4.26 (d, J = 11.6 Hz, 1H), 3.97 (d, J = 10.8 Hz, 1H), 3.19 (d, J = 10.8 Hz, 1H), 2.35 (d, J = 7.8 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 202.5, 202.0, 201.5, 201.2, 158.3, 153.1, 144.1, 142.6, 142.4, 141.7, 140.1, 135.7, 135.4, 135.1, 135.0, 133.6, 133.2, 132.7, 131.5, 131.1, 130.2, 129.9, 128.7, 126.1, 125.8, 122.8, 122.5, 122.3, 117.2, 114.6, 114.4, 113.3, 63.6, 62.3, 56.4, 55.7, 55.6, 55.0, 55.0, 50.3, 50.2, 44.5, 42.8, 32.3; IR (KBr) ν: 3061, 2930, 2830, 1738, 1703, 1598, 1511, 1458, 1343, 1242, 1174, 1104, 1034, 960, 827, 765 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C42H33BrNO6 ([M + H]+), 726.1491; found, 726.1485.

2′-(2-Bromophenyl)-4′-(4-fluorophenyl)-6′-((4-methoxyphenyl)amino)dispiro[indene-2,1′-cyclohexane-3′,2″-indene]-1,1″,3,3″-tetraone (5n)

The product is obtained as a yellow solid, 85%, 0303 g, mp 146–148 °C; 1H NMR (400 MHz, CDCl3): δ trans-isomer: 8.08 (d, J = 9.0 Hz, 1H), 7.75–7.69 (m, 2H), 7.62–7.39 (m, 5H), 7.12–6.90 (m, 7H), 6.67–6.47 (m, 5H), 5.14 (d, J = 12.8 Hz, 1H), 5.06–4.01 (m, 2H), 3.70 (d, J = 12.7 Hz, 1H), 3.56–3.48 (m, 1H), 1.99 (d, J = 15.8 Hz, 1H); cis-isomer: 7.90 (d, J = 8.3 Hz, 1H), 7.12–6.90 (m, 8H), 5.33 (s, 1H), 4.74 (br s, 1H), 4.36 (d, J = 14.0 Hz, 1H), 4.23 (d, J = 12.8 Hz, 1H), 3.27–3.17 (m, 1H), 2.37 (d, J = 11.0 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 202.3, 202.0, 201.3, 201.0, 162.8, 160.4, 153.2, 144.0, 142.5, 142.4, 141.6, 139.9, 135.4, 135.3, 135.2, 135.1, 134.8, 133.4, 133.2, 132.6, 130.8, 130.7, 130.4, 128.7, 126.1, 125.8, 122.8, 122.6, 122.3, 117.2, 114.8, 114.6, 63.5, 62.1, 56.2, 55.6, 50.2, 50.2, 32.1.; IR (KBr) ν: 3064, 1740, 1705, 1595, 1511, 1339, 1245, 1169, 1121, 1030, 832, 764, 728 cm–1; MS (m/z): HRMS (ESI-TOF) calcd for C41H30BrFNO5 ([M + H]+), 714.1291; found, 714.1280.